如图,已知
中,
平分
,且
,点
是
延长线上一点,且
,过点
作
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/f70ea310-d7f1-4f27-8ed9-bdf7fae9c9e8.png?resizew=125)
(1)若
,求等腰三角形
与等腰三角形
的底角的度数;
(2)求证:
;
(3)判断
的形状并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a26c2c53046cbfe83f84f5393373589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/680b53673467d5e29454148104e32fec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c4567ae3f7827588855f39569d4f7c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/f70ea310-d7f1-4f27-8ed9-bdf7fae9c9e8.png?resizew=125)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3104c05e255396a91038e2896aedf5cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1f1d7219cd40346442b33dba84deb5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2192d30780387676792c40d416544d9.png)
(3)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36691f0269294ecae8f00b7bce97756c.png)
更新时间:2021-01-12 08:51:18
|
【知识点】 相似三角形的判定与性质综合
相似题推荐
解答题-证明题
|
较难
(0.4)
解题方法
【推荐1】如图1,Rt△ABC中,点D,E分别为直角边AC,BC上的点,若满足AD2+BE2=DE2,则称DE为R△ABC的“完美分割线”.显然,当DE为△ABC的中位线时,DE是△ABC的一条完美分割线.
![](https://img.xkw.com/dksih/QBM/2020/5/21/2467242279059456/2467460608589824/STEM/038a08ee41c243acbe1f66f7b353e584.png?resizew=492)
(1)如图1,AB=10,cosA=
,AD=3,若DE为完美分割线,则BE的长是 .
(2)如图2,对AC边上的点D,在Rt△ABC中的斜边AB上取点P,使得DP=DA,过点P画PE⊥PD交BC于点E,连结DE,求证:DE是直角△ABC的完美分割线.
(3)如图3,在Rt△ABC中,AC=10,BC=5,DE是其完美分割线,点P是斜边AB的中点,连结PD、PE,求cos∠PDE的值.
![](https://img.xkw.com/dksih/QBM/2020/5/21/2467242279059456/2467460608589824/STEM/038a08ee41c243acbe1f66f7b353e584.png?resizew=492)
(1)如图1,AB=10,cosA=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7294f5ae2a24ff42e84cd9773b2a7287.png)
(2)如图2,对AC边上的点D,在Rt△ABC中的斜边AB上取点P,使得DP=DA,过点P画PE⊥PD交BC于点E,连结DE,求证:DE是直角△ABC的完美分割线.
(3)如图3,在Rt△ABC中,AC=10,BC=5,DE是其完美分割线,点P是斜边AB的中点,连结PD、PE,求cos∠PDE的值.
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解答题-证明题
|
较难
(0.4)
【推荐2】【基础巩固】(1)如图1,
中,点D,E在边
上,
,
,求证:
;
【尝试应用】(2)如图2,
中,点E,F在对角线
上,且
,求证:
;
【拓展提高】(3)在(2)的基础上,若
,
,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d212c1709b8e72a055cf1b5381ef64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22f8592b15fc64f33be4fc80c5053c6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1c1124252175a195949c89409c0f37e.png)
【尝试应用】(2)如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5138a9f70d5e8b0580e30fef6eb7baef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91017ae019041795e53ddf4dd386c575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86d1125b47dec1c5e93143ee59ad862a.png)
【拓展提高】(3)在(2)的基础上,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/070bc896d35495237fd65576e9b6f88e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e7c422a19b68b8b4cd484d22897e3a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df678c4a265d54ee028e750d74d67a27.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e8c16febdbd7a854fbb52d25e740ec2.png)
您最近一年使用:0次
【推荐3】如图,在Rt△ABC中,∠B=90°,AB=6cm,BC=8cm,点D从点A出发以1cm/s的速度运动到点C停止.作DE⊥AC交边AB或BC于点E,以DE为边向右作正方形DEFG.设点D的运动时间为t(s).
![](https://img.xkw.com/dksih/QBM/2018/3/8/1897634786361344/1904810129416192/STEM/2d2afe2c-05aa-4b7a-b566-b43ee398409a.png?resizew=244)
(1)求AC的长.
(2)请用含t的代数式表示线段DE的长.
(3)当点F在边BC上时,求t的值.
(4)设正方形DEFG与△ABC重叠部分图形的面积为S(cm2),当重叠部分图形为四边形时,求S与t之间的函数关系式.
![](https://img.xkw.com/dksih/QBM/2018/3/8/1897634786361344/1904810129416192/STEM/2d2afe2c-05aa-4b7a-b566-b43ee398409a.png?resizew=244)
(1)求AC的长.
(2)请用含t的代数式表示线段DE的长.
(3)当点F在边BC上时,求t的值.
(4)设正方形DEFG与△ABC重叠部分图形的面积为S(cm2),当重叠部分图形为四边形时,求S与t之间的函数关系式.
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