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【330531】第6章《平行四边形》单元测试试卷及答案

时间:2025-02-09 11:37:15 作者: 字数:8938字

6章《平行四边形》单元测试试卷及答案

(本试卷满分:100分,时间:90分钟)

一、选择题(每小题3分,共30分)

1.如图,在 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的垂直平分线交 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 于点 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,则△ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长是( )

A.6 B.8 C.9 D.10

DrawObject1

DrawObject2





2.如图, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长是 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,△ABC的周长是 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,则 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的长为( )

A. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> B. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> C. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> D. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

3.正八边形的每个内角为( )

A.120° B.135° C.140° D.144°

4.ABCD中,下列结论一定正确的是(

A.ACBD B.A+B=180° C.AB=AD D.AC

5.多边形的内角中,锐角的个数最多为(

A.1 B.2 C.3 D.4

6.2013•四川泸州中考)在四边形ABCD中,对角线ACBD相交于点O,下列条件不能判定这个四边形是平行四边形的是(  )

A.ABDCADBC B.AB=DCAD=BC

C.AO=COBO=DO D.ABDCAD=BC

7.2013•海南中考)如图,在ABCD中,ACBD相交于点O,则下列结论不一定成立的是(  )

A.BO=DO B.CD=AB C.BAD=BCD D.AC=BD

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

8.2012•四川巴中中考)不能判定一个四边形是平行四边形的条件是(  )

A.两组对边分别平行 B.一组对边平行另一组对边相等

C.一组对边平行且相等 D.两组对边分别相等

9.2013•广东湛江中考)已知一个多边形的内角和是540°,则这个多边形是(  )

A.四边形 B.五边形 C.六边形 D.七边形

10.如图,在ABCD中,对角线ACBD相交于点O,点EF分别是边ADAB的中点,EFAC于点H,则 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的值为(  )

A.1 B. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> C. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> D. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>






二、填空题(每小题3分,共24分)

11.如图,在ABCD中,∠ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,那么 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> _____ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ______ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

DrawObject3





12.如图,在 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 分别为边 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的中点,则图中共有 个平行四边形.

13.如图,在△ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中,点 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 分别是 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的中点, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,则 C的度数为________. 来源:http://www.bcjy123.com/tiku/

14.若凸 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 边形的内角和为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,则从一个顶点出发引出的对角线条数是__________.

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

15.若一个多边形的内角和是外角和的5倍,则这个多边形是 边形.

16.如图,在四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中,  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,再添加一个条件 (写出一个即可),则四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 是平行四边形.(图形中不再添加辅助线)

1 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 7. 如图,在ABCD中,对角线ACBD相交于点E,∠AEB=45°,BD=2,将△ABC沿AC所在直线翻折180°到其原来所在的同一平面内,若点B的落点记为B′,DB的长为 .


18.如图,ABCDDCFE的周长相等,且∠BAD=60°,∠F=110°,则∠DAE的度数为 .









三、解答题(共46分)

19.6分)已知 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长为40 cm <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,求 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的长.




20.6分)已知,在 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中,∠ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的平分线分 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 两条线段,求 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长.





21.6分)如图,四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 是平行四边形, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,求 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的长.

DrawObject4

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>











22.6分)如图,在四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,求四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长. 来源:http://www.bcjy123.com/tiku/









2 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 3.6分)已知:如图,在 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中,对角线 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 相交于点 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 过点 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 分别交 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 于点 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 求证: <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

DrawObject5











24.6分)已知:如图,在 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 是对角线 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 上的两点,且 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 求证: <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>













2 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 5.(10)如图,在Rt△ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中,∠C=90°,∠B=60° <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>EF分别为边ACAB的中点.

1)求∠A的度数;

2)求 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的长.






参考答案

1.B 解析:在 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

因为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的垂直平分线交 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 于点 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

所以△ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

2.D 解析:因为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长是28 cm,所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

因为△ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长是 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

3.B 解析:∵ 正八边形的外角和为360°,∴ 正八边形的每个外角的度数 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,∴ 正八边形的每个内角 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

4.B 解析:平行四边形的对角线互相平分但不一定垂直,所以选项A错误;平行四边形的邻角互补,所以选项B正确;平行四边形的对边相等但邻边不一定相等,所以选项C错误;平行四边形的对角相等,所以∠A=C,所以选项D错误.

5.C 解析:因为多边形的外角和为360°,所以一个多边形中最多有三个外角为钝角,否则外角和就超过360°,因此可得一个多边形中最多有三个内角为锐角,否则对应的外角就超过三个钝角了. 来源:http://www.bcjy123.com/tiku/

6.D 解析:A.由“ABDCADBC可知,四边形ABCD的两组对边分别平行,则该四边形是平行四边形,故本选项不符合题意;

B.由“AB=DCAD=BC可知,四边形ABCD的两组对边分别相等,则该四边形是平行四边形,故本选项不符合题意;

C.由“AO=COBO=DO可知,四边形ABCD的两条对角线互相平分,则该四边形是平行四边形,故本选项不符合题意;

D.由“ABDCAD=BC可知,四边形ABCD的一组对边平行,另一组对边相等,据此不能判定该四边形是平行四边形,故本选项符合题意.

7.D 解析:A.∵ 四边形ABCD是平行四边形,∴ OB=OD(平行四边形的对角线互相平分),不符合题意;

B.∵ 四边形ABCD是平行四边形,∴ CD=AB,不符合题意;

C.∵ 四边形ABCD是平行四边形,∴ BAD=BCD,不符合题意;

D.根据四边形ABCD是平行四边形不能推出AC=BD,符合题意.

8.B 解析:根据平行四边形的判定:①两组对边分别平行的四边形是平行四边形;②两组对边分别相等的四边形是平行四边形;③两组对角分别相等的四边形是平行四边形; ④对角线互相平分的四边形是平行四边形;⑤一组对边平行且相等的四边形是平行四边形,即可得出答案.根据平行四边形的判定,ADC均符合是平行四边形的条件,B不能判定是平行四边形.

9.B 解析:根据多边形的内角和可得 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,解得 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,则这个多边形是五边形.

10.C 解析:∵ EF分别是边ADAB的中点,∴ AH=HO.

平行四边形ABCD的对角线ACBD相交于点O,∴ AO=CO

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,∴  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .故选C.

11. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 12 解析:因为四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 是平行四边形,

所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

又因为∠ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

12.4 解析:因为在ABCD中,EF分别为边ABDC的中点,所以  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .ABCD,所以四边形AEFDCFEBDFBE都是平行四边形,再加上ABCD本身,共有4个平行四边形,故答案为4

13. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 解析:由题意,得 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

DE分别是ABAC的中点,∴ DE是△ABC的中位线,

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,∴  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

14.6 解析:由题意,得 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 解得 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 这个多边形为九边形,所以从九边形的一个顶点引出的对角线条数为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

15.十二 解析:设这个多边形是 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 边形,根据题意列方程,得 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,解得 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,即此多边形的边数是12


16. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 或∠ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> (答案不唯一)

17. <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 解析:∵ 四边形ABCD是平行四边形,∴ BE=DE= <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> BD=1.

由折叠知 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

Rt△ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

18.25° 解析:因为ABCDDCFE的周长相等,且DC为公共边,

所以AD=DE,所以∠DAE=∠DEA.

因为ABDC,DCEF,所以ABEF,所以∠BAE+∠FEA=180°

即∠BAD+∠DAE+∠FED+∠DEA=180°.

因为DECF,∠F=110°,

所以∠FED+∠F=180°,则∠FED=70°.

因为∠BAD=60°,所以60°+70°+2∠DAE=180°,所以∠DAE=25°.

19.解:因为四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 是平行四边形,所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> cm <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> cm

又因为平行四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长为40 cm

所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,解得 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

20.解:设∠ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的平分线交 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 点,如图.

因为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以∠ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

DrawObject6 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以∠ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 时, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

21.解:因为四边形ABCD是平行四边形,

所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

因为 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

所以 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

22.解:∵  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,∴  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

又∵  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,∴ ∠ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> , ∴  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,

四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 是平行四边形 , ∴  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 的周长 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

23.证明:∵ 四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 是平行四边形,∴  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

∴ △ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ≌△ <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,故 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

24.证明:∵ 四边形 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 是平行四边形, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> 中, <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> ,∴  <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> .

25.解:(1)∵ RtABC中,∠C=90°,∠B=60°

∴∠A=90° <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a> B=30°,即∠A的度数是30°.

2)由(1)知,∠A=30°

RtABC中,∠C=90°,∠A=30°AB=8 cm

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>

EF分别为边ACAB的中点,

EF是△ABC的中位线,

 <a href="/tags/1/" title="单元" class="c1" target="_blank">单元</a> <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/46/" title="答案" class="c1" target="_blank">答案</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/58/" title="平行" class="c1" target="_blank">平行</a> <a href="/tags/82/" title="平行四边形" class="c1" target="_blank">平行四边形</a>