【问题提出】:
(1)如图1,在Rt△ABC中,∠ACB=90°,AC>BC,∠ACB的平分线交AB于点P,过点P分别作PE⊥AC,PF⊥BC,垂足分别为E,F,则图1中四边形PECF的形状为 .请写出证明过程.
【问题探究】:
(2)如图2,在Rt△ABC中,∠ACB=90°,AB=10cm,AC=8cm,∠ACB的平分线交AB于点P,过点P分别作PE⊥AC,PF⊥BC,垂足分别为E,F,求四边形PECF的面积.请写出解答过程.
(1)如图1,在Rt△ABC中,∠ACB=90°,AC>BC,∠ACB的平分线交AB于点P,过点P分别作PE⊥AC,PF⊥BC,垂足分别为E,F,则图1中四边形PECF的形状为 .请写出证明过程.
【问题探究】:
(2)如图2,在Rt△ABC中,∠ACB=90°,AB=10cm,AC=8cm,∠ACB的平分线交AB于点P,过点P分别作PE⊥AC,PF⊥BC,垂足分别为E,F,求四边形PECF的面积.请写出解答过程.
![](https://img.xkw.com/dksih/QBM/2021/11/12/2849477860745216/2853445661818880/STEM/c57d13ba-18d7-49c9-a87d-c5fc1a96c701.png)
更新时间:2021-11-17 21:32:58
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【推荐1】如图,已知:的
、
的外角平分线交于点
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【推荐2】如图,BD是△ABC的角平分线,点E,F分别在BC、AB上,且DE∥AB,EF∥AC.
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(1)求证:BE=AF;
(2)若∠ABC=60°,BD=6,求四边形ADEF的面积.
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(1)求证:BE=AF;
(2)若∠ABC=60°,BD=6,求四边形ADEF的面积.
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【推荐1】如图,在
中,
,
,
是等边三角形,将四边形ACBD沿直线EF折叠,使D与C重合,CE、CF分别交AB于点G、H.
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(1)求证:
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(2)
与
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(3)若
,求
的值.
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(1)求证:
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(2)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec6aaa4eac0d4ae4dedb7aa8a746c866.png)
(3)若
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【推荐2】如图,在直角梯形
中,
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,
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的速度沿
运动,点Q从C开始沿
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(1)t为何值时,四边形
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(2)t为何值时,四边形
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(3)是否存在某一时刻t,使线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
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【推荐1】如图,在
中,过点
作
于点
,点
在边
上,
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(2)若
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【推荐2】如图,在▱ABCD中,DE⊥AB,BF⊥CD,垂足分别为E,F.求证:BE=DF.
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【推荐1】阅读材料,并解决问题.
图①是一个长为
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(1)请你仔细观察图②,并用两种不同的方法表示大正方形的面积;
方法1:______方法2:______
(2)由(1)你能得出什么结论?用含
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①已知
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(1)请你仔细观察图②,并用两种不同的方法表示大正方形的面积;
方法1:______方法2:______
(2)由(1)你能得出什么结论?用含
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【推荐2】如图,点M是
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