矩形ABCD中,AB=2,AD=4,将矩形ABCD绕点C顺时针旋转至矩形EGCF(其中E、G、F分别与A、B、D对应).
(1)如图1,当点G落在AD边上时,直接写出AG的长为 ;
(2)如图2,当点G落在线段AE上时,AD与CG交于点H,求GH的长;
(3)如图3,记O为矩形ABCD对角线的交点,S为△OGE的面积,求S的取值范围.
(1)如图1,当点G落在AD边上时,直接写出AG的长为 ;
(2)如图2,当点G落在线段AE上时,AD与CG交于点H,求GH的长;
(3)如图3,记O为矩形ABCD对角线的交点,S为△OGE的面积,求S的取值范围.
![](https://img.xkw.com/dksih/QBM/2020/1/20/2380921761382400/2381247250038784/STEM/3aab1f4907304cce9cee68edead02918.png?resizew=467)
更新时间:2020-01-20 18:02:50
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相似题推荐
解答题-证明题
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【推荐1】定义:我们知道,四边形的一条对角线把这个四边形分成了两个三角形,如果这两个三角形相似(不全等),我们就把这条对角线叫做这个四边形的“相似对角线”.
(1)如图1,已知四边形
在正方形网格中,顶点都在格点上,判断:四边形
______(填“是”或“不是”)以
为“相似对角线”的四边形;
(2)如图
,在四边形
中,
,
,对角线
平分
.求证:
是四边形
的“相似对角线”;
(3)如图
,已知
是四边形
的“相似对角线”,
.连接
,若
的面积为
,求
的长.
(1)如图1,已知四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(2)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2e30ffe627436f57ecf46b89c57bb21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70d9fce8285e9134f63924be5cd8770f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(3)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83f1f880e5ffbff036953acaca90c41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/611f100dcfa7803db6eb233e2e7f2dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a54f7ef0b54526b4b66e3825f1a997a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e55e398e8520d8a36fb5a625a085b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36e5e61804ce550636a0354e0a78a22d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41322821ce31416fdac8dd6e0aa41c71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83f1f880e5ffbff036953acaca90c41.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/5a1ef796-ece2-46f1-9407-b0ac2aeec336.png?resizew=499)
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【推荐2】问题情境:在
中,
,
,
,
是边
上的高,点
为
上一点,连接
,过点
作
交
于点F.
猜想与证明:
的中点时,试判断点
是否为边
的中点;
(2)如图2,连接
,试判断
与
是否相似;
问题解决:
(3)如图3,当
时,试求线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07140f277a35733d8c97577ccdd4e3ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c175c239742c7ba8fd67a6d5f99cb1b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
猜想与证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)如图2,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
问题解决:
(3)如图3,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac679f877d3e3b3acef1f1f8e3654b4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
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【推荐1】问题背景:如图1,在矩形ABCD中,AB=2
,∠ABD=30°,点E是边AB的中点,过点E作EF⊥AB交BD于点F.
![](https://img.xkw.com/dksih/QBM/2022/2/24/2923339710251008/2924934673539072/STEM/91334283-cf80-4a56-8412-10860f402fae.png?resizew=426)
(1)在一次数学活动中,小王同学将图1中的△BEF绕点B按逆时针方向旋转90°,如图2所示,得到结论:①
=______ ;②直线AE与DF所夹锐角的度数为 _______.
(2)小王同学继续将△BEF绕点B按逆时针方向旋转,旋转至如图3所示位置.请问探究(1)中的结论是否仍然成立?并说明理由.
(3)根据以上探究,将△BEF绕点B按顺时针方向旋转180°,设直线AE与DF的交点为P,在旋转过程中,点P的位置也随之改变,请思考点P运动的轨迹,直接写出点P运动的路程_______.(结果保留π)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/2022/2/24/2923339710251008/2924934673539072/STEM/91334283-cf80-4a56-8412-10860f402fae.png?resizew=426)
(1)在一次数学活动中,小王同学将图1中的△BEF绕点B按逆时针方向旋转90°,如图2所示,得到结论:①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14a4c86103260c233b26ec7dc50ad1ed.png)
(2)小王同学继续将△BEF绕点B按逆时针方向旋转,旋转至如图3所示位置.请问探究(1)中的结论是否仍然成立?并说明理由.
(3)根据以上探究,将△BEF绕点B按顺时针方向旋转180°,设直线AE与DF的交点为P,在旋转过程中,点P的位置也随之改变,请思考点P运动的轨迹,直接写出点P运动的路程_______.(结果保留π)
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【推荐2】在平面直角坐标系中,矩形ABCO的边OA在y轴的正半轴上,OC在x轴的负半轴上.
,0),
①如图(1),求证∠AOB=60°;
②如图(2),点P,Q分别在BO和OA上,BP=OQ,直接写出AP+CQ的最小值;
(2)如图(3),过BO中点H的直线交y轴于点N,NH⊥BO,菱形ODEF的边OD在x轴的正半轴上,E,F在第一象限;M为BE的中点,FM⊥MN.求证:∠ODE=2∠BON.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
①如图(1),求证∠AOB=60°;
②如图(2),点P,Q分别在BO和OA上,BP=OQ,直接写出AP+CQ的最小值;
(2)如图(3),过BO中点H的直线交y轴于点N,NH⊥BO,菱形ODEF的边OD在x轴的正半轴上,E,F在第一象限;M为BE的中点,FM⊥MN.求证:∠ODE=2∠BON.
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【推荐1】如图,在四边形ABCD中,∠A=∠B=90°,AD=4,BC=10,sinC=
,以AB为直径作⊙O,把⊙O沿水平方向平移x个单位,得到⊙O′,A'B'为直径AB平移后的对应线段.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/12/2733e8e2-8293-44f1-81ec-241d9581730d.png?resizew=307)
(1)当x=0,且M为⊙O上一点时,求DM的最大值;
(2)当B′与C重合时,设⊙O′与CD相交于点N,求点N到AB的距离;
(3)当⊙O′与CD相切时,直接写出x的值 .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7294f5ae2a24ff42e84cd9773b2a7287.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/12/2733e8e2-8293-44f1-81ec-241d9581730d.png?resizew=307)
(1)当x=0,且M为⊙O上一点时,求DM的最大值;
(2)当B′与C重合时,设⊙O′与CD相交于点N,求点N到AB的距离;
(3)当⊙O′与CD相切时,直接写出x的值 .
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【推荐2】【发现问题】爱好数学的小明在做作业时碰到这样的一道题目:
如图①,点O为坐标原点,
的半径为1,点
,动点B在
上,连结AB,作等边
B,C为顺时针顺序
,求OC的最大值.
【解决问题】小明经过多次的尝试与探索,终于得到解题思路:在图①中,连接OB,以OB为边在OB的左侧作等边三角形BOE,连接AE.
![](https://img.xkw.com/dksih/QBM/2021/1/20/2640179275292672/2645214664990720/STEM/58fecab612d54aa5888407651109c084.png?resizew=458)
请你找出图中与OC相等的线段,并说明理由;
线段OC的最大值为_____.
【灵活运用】
如图②,在平面直角坐标系中,点A的坐标为
,点B的坐标为
,点P为线段AB外一动点,且
,求线段AM长的最大值及此时点P的坐标.
【迁移拓展】
如图③
,点D是以BC为直径的半圆上不同于B、C的一个动点,以BD为边作等边
,请直接写出AC的最大值,最小值.
如图①,点O为坐标原点,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870fa9709a70b3d99118b4b671fb016f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd80ee0b5e585ca267ceeb47d6f8b8c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870fa9709a70b3d99118b4b671fb016f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dc307c79e471d7bab0bf25bb4883f96.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
【解决问题】小明经过多次的尝试与探索,终于得到解题思路:在图①中,连接OB,以OB为边在OB的左侧作等边三角形BOE,连接AE.
![](https://img.xkw.com/dksih/QBM/2021/1/20/2640179275292672/2645214664990720/STEM/58fecab612d54aa5888407651109c084.png?resizew=458)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bf6c84731e5e1bd335ecfc2d36c3d81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f53190d6ead827a6338b9de847aeaf1.png)
【灵活运用】
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f62295c36d2e2174908c2bec0eb5b30f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fab8a0cc6504aa4c3a38006f5394b4c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b569572c8d9bf05d78d3ab741e68bb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fcbaa7910d5886bf92320d644d64ab6.png)
【迁移拓展】
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b49be5fb800b66cdb284b864e8f04a85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed99ce25ed3a5a017f66d974e7421d47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af7ec89310dae69a9b978060f523cd5b.png)
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【推荐1】如图,将
和
拼成一个四边形
,其中
,
,
,过点
作
,垂足为点
,连接
.
![](https://img.xkw.com/dksih/QBM/2021/1/27/2645251474341888/2669390766424064/STEM/417583166df1445f847f2b4052d8098a.png?resizew=121)
(1)探索线段
、
、
之间有何等量关系,并加以证明;
(2)设
,将
绕点
旋转得
,连接
、
,请直接写出
的最大面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90b40c2b0ab8e1cfe5112d428b4b829f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b27e47690ed332c573186992b6d25654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4795ee1f96b430529934e2231b38885d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3402ea855e2ae2dcd98f607bef4fdd6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e3f5dc11efe60b4fd9a13b1d6b83842.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://img.xkw.com/dksih/QBM/2021/1/27/2645251474341888/2669390766424064/STEM/417583166df1445f847f2b4052d8098a.png?resizew=121)
(1)探索线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb49df05f2e31d005735c3f14a21d30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebf893998e0140bbe4fd7f2358d2d0f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6024fd4532f5f981deac4582c799a6ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bf97f9082d7f40bc680cc2c58865309.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d65d985e62ff94f7689955c387fac28.png)
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【推荐2】阅读情境:在综合实践课上,同学们探究“全等的等腰直角三角形图形变化问题”
如图1,
,其中
,
,此时,点
与点
重合,
操作探究1:(1)小凡将图1中的两个全等的
和
按图2方式摆放,点
落在
上,
所在直线交
所在直线于点
,连结
,求证:
.
操作探究2:(2)小彬将图1中的
绕点
按逆时针方向旋转角度![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
,然后,分别延长
,
,它们相交于点
.如图3,在操作中,小彬提出如下问题,请你解答:
①
时,求证:
为等边三角形;
②当
__________时,
.(直接回答即可)
操作探究3:(3)小颖将图1中的
绕点
按顺时针方向旋转角度![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
,线段
和
相交于点
,在操作中,小颖提出如下问题,请你解答:
①如图4,当
时,直接写出线段
的长为_________.
②如图5,当旋转到点
是边
的中点时,直接写出线段
的长为____________.
如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9289ab1d719a78a8e0a260151386eac7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59281d3136f2c67c078d98842171224d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d69590ff4327d97efe098ca7ecc9c2cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/26/6af06e96-6f30-44a5-b55c-4cdc64b12746.png?resizew=615)
操作探究1:(1)小凡将图1中的两个全等的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f460edcced5597615113c0fdc95b1dfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3d1d3c51f36c9913364a8fc8c643530.png)
操作探究2:(2)小彬将图1中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3cc97a6f5f711b174535317d7b87f1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6c96cb3ac8290e09c55d4eb336a8608.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7807f6a0d316671ed34c23e32fc7408.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ecd92d6d7d10f570c1413f2724001a9.png)
操作探究3:(3)小颖将图1中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b85cb004ce99e4afe264766fc0483fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
①如图4,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b235c077d324c45527cee213a48c1fee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
②如图5,当旋转到点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐3】如图,在两个全等的等腰直角三角形ABC和EDC中,∠ACB=∠ECD=90°,点A与点E重合,点D与点B重合.现△ABC不动,把△EDC绕点C按顺时针方向旋转,旋转角为α(0°<α<90°).
(1)如图②,AB与CE交于点F,ED与AB,BC分别交于点M,H.求证:CF=CH;
(2)如图③,当α=45°时,试判断四边形ACDM的形状,并说明理由;
(3)如图②,在△EDC绕点C旋转的过程中,连结BD,当旋转角α的度数为多少时,△BDH是等腰三角形?
(1)如图②,AB与CE交于点F,ED与AB,BC分别交于点M,H.求证:CF=CH;
(2)如图③,当α=45°时,试判断四边形ACDM的形状,并说明理由;
(3)如图②,在△EDC绕点C旋转的过程中,连结BD,当旋转角α的度数为多少时,△BDH是等腰三角形?
![](https://img.xkw.com/dksih/QBM/2018/8/17/2012488259117056/2017335187628032/STEM/d40081eab61a4db09a4508d8e5c5a4cd.png?resizew=115)
![](https://img.xkw.com/dksih/QBM/2018/8/17/2012488259117056/2017335187628032/STEM/88fe02132a594fb28ad2c01df921a888.png?resizew=130)
![](https://img.xkw.com/dksih/QBM/2018/8/17/2012488259117056/2017335187628032/STEM/a95a612c90cb44c4aeffc02ad886d896.png?resizew=141)
您最近一年使用:0次