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【330943】4.1 成比例线段(第2课时)

时间:2025-01-21 13:26:29 作者: 字数:738字
简介:







4.1成比例线段(第2课时)

一、问题引入:

1、如图, <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a> 的值相等吗? <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a> 的值又是多少?在求解过程中,你有什么发现?

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a>














2、已知,abcdef六个数.

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a>


3、归纳出等比性质__________________________________ ______________.

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a> 、基础训练:



2、已知 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a> a+b=8,ab=____________.


 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a> 、例题展示:







四、课堂检测:

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a>

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a>

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a>











4、如图,已知每个小方格的边长均为1,求AB,DE,BC,DC,AC,EC的长,并计算△ABC与△EDC的周长比.

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/175/" title="线段" class="c1" target="_blank">线段</a>