如图,在
中,
,
是
的中点。在射线
上任意取一点
,连接
,将线段
绕点
逆时针方向旋转80°,点
的对应点是点
,连接
.
(1)如图1,当点
落在射线
上时,
①
_________________°;
②直线
与直线
的位置关系是______________________。
![](https://img.xkw.com/dksih/QBM/2019/12/27/2364171071315968/2367065837338624/STEM/4991ef49027941508bad9c28e572735e.png?resizew=208)
(2)如图2,当点
落在射线
的左侧时,试判断直线
与直线
的位置关系,并证明你的结论。
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/283d07f2fafe79c207a20d40193e2516.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ed3797a759dca7272c4f8a2434423ff.png)
(1)如图1,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b62c64a9822fed4a36bbeca730b28530.png)
②直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2019/12/27/2364171071315968/2367065837338624/STEM/4991ef49027941508bad9c28e572735e.png?resizew=208)
(2)如图2,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2019/12/27/2364171071315968/2367065837338624/STEM/501e557879b34081be2198866ee7c394.png?resizew=225)
更新时间:2019-12-31 17:10:41
|
相似题推荐
解答题-证明题
|
较难
(0.4)
【推荐1】已知三角形ABC和同一平面内的点D.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/18/35de0fcc-6687-478b-8de9-c15ce2c2ed8b.png?resizew=518)
(1)如图1,点D在边BC上,过点D作DE
BA,交AC于点E,DF
CA,交AB于点F.
①依题意,在图1中朴全图形;
②若∠EDF=89°,求∠A的度数;
③通过图形说明∠A+∠B+∠C=180°(三角形的内角和为180°);
(2)如图2,若点D在BC的延长线上,DF
CA,DE在BC上方,且∠EDF=∠A,判断DE与BA的位置关系,并证明;
(3)若D是三角形ABC外部的一个动点(不在三角形三条边所在的直线上),过点D作DE
BA交直线AC于点E,DF
CA交直线AB于点F,直接写出∠EDF与∠A的数量关系.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/18/35de0fcc-6687-478b-8de9-c15ce2c2ed8b.png?resizew=518)
(1)如图1,点D在边BC上,过点D作DE
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb31ef428bd9de9bc875b343feded3c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb31ef428bd9de9bc875b343feded3c7.png)
①依题意,在图1中朴全图形;
②若∠EDF=89°,求∠A的度数;
③通过图形说明∠A+∠B+∠C=180°(三角形的内角和为180°);
(2)如图2,若点D在BC的延长线上,DF
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
(3)若D是三角形ABC外部的一个动点(不在三角形三条边所在的直线上),过点D作DE
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
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名校
【推荐2】如图1,已知直线
与直线
交于点E,直线
与直线
交于点F,
平分
交直线
于点M,且
.
;
(2)点G是射线
上的一个动点(不与点M、F重合),
平分
交直线
于点H,过点H作
交直线
于点N,设
.
①如图2,当点G在点F的右侧时,若
,求
的值;
②当点G在运动过程中,
和
之间有怎样的数量关系?直接写出你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b46c607b3deac746c0ef3389ad8f65c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b6a23d521606a35298bbf147f7f830c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2d3febf781db5eb6d3596b88818685e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.png)
(2)点G是射线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be2e2c0d4ac2bd79f6cea7a9b1a50662.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589786dd7c3a2679c3230b671cd232d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d335bf8cb2e6e5e50d0e03a14d1f48d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe945309e74182386feae8fc0115f4f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65d81aff7931f793a7a3acd832f71d3.png)
①如图2,当点G在点F的右侧时,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b145899cf97c9576dac1a93ed4e44118.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
②当点G在运动过程中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
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解答题-问答题
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名校
【推荐1】某同学在一次课外活动中,用硬纸片做了两个直角三角形,见图(1)、图(2).在图(1)中,∠B=90°,∠A=30°;图(2)中,∠D=90°,∠F=45°.图(3)是该同学所做的一个实验:他将△DEF的直角边DE与△ABC的斜边AC重合在一起,并将△DEF沿AC方向移动.在移动过程中,D、E两点始终在AC边上,移动开始时,点D与点A重合.
(1)△DEF在移动过程中,∠FCE与∠CFE度数之和是否为定值,请加以说明;
(2)能否将△DEF移动至某位置,使F、C的连线与AB平行?若能,求出∠CFE的度数;若不能,请说明理由.
(1)△DEF在移动过程中,∠FCE与∠CFE度数之和是否为定值,请加以说明;
(2)能否将△DEF移动至某位置,使F、C的连线与AB平行?若能,求出∠CFE的度数;若不能,请说明理由.
![](https://img.xkw.com/dksih/QBM/2019/3/14/2160387200802816/null/STEM/eeae2ee0aa4149d5bc7ec50cdf5d16e0.png?resizew=382)
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【推荐2】【感知】如图①,在四边形
中,点
在边
上(点
不与点
、
重合),
.易证:
(不要求证明).
【探究】如图②,在四边形
中,点
在边
上(点
不与点
、
重合),
.
(1)求证:
.
(2)若
,
,
,求
的长.
【应用】如图③,在
中,
,
,点
在边
上(点
不与点
、
重合),连结
,作
,
与边
交于点
.当
时,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f8e63c767b1a19f79285d123c080211.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07e004d1939142de86e5dfa9386c8049.png)
【探究】如图②,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71e7fea3b9599d8021cc551f8d93e524.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07e004d1939142de86e5dfa9386c8049.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/682c9d9b6ad1bc45ddbd6dd01060207b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9c893198d60f9129971aabf596d0ec2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65fc998d33cdf37c272f79cfd64b7b99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
【应用】如图③,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08313da7b66283d2e0b3987f3e6761f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9f9b23edebed6f00741022b69727de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0db08b3357087e99df796adef5ec217d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://img.xkw.com/dksih/QBM/2019/12/6/2349307849105408/2350148648361984/STEM/ae5765ef310e417ebb7f4690b515169b.png?resizew=435)
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解答题-问答题
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较难
(0.4)
【推荐1】如图,
中,
,
,
,
垂足为
.点
从点
出发,沿
方向匀速运动,速度为
;同时,点
从点
出发,沿
方向匀速运动,速度为
.过点
作
交
于点
,连接
.设运动时间为
.解答下列问题:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/16/1c59a461-6611-4e23-be10-e8b08918d12b.png?resizew=275)
(1)线段
__________
;则用含
的代数式表示
__________
;
(2)当四边形
的面积为
,求
的值;
(3)在运动过程中,是否存在某一时刻
,使点
在
的垂直平分线上?若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/734893aa97a3605a1a53050f857b65d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d68a7c1620c784fc641700fa004a8ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b27e47690ed332c573186992b6d25654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d989a128e30a701dfff5592476a76bab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5631e6ec24d3d67bf4592313b6b3f4f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02e11716717079cae131ed72f6318a78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94a1cc70dc19b7bc5fd07cc00c92fd08.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/16/1c59a461-6611-4e23-be10-e8b08918d12b.png?resizew=275)
(1)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9f63d194aa0d4091618b6f41f569ee2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa9fbcfb9595e2f031aa691db4564b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb4506d27656f9009b41c6d2fe44b47e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa9fbcfb9595e2f031aa691db4564b.png)
(2)当四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1195c8aeabf1925d6980b8de505e4050.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dddbfaf99b991cb69db5ecbad906e4f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(3)在运动过程中,是否存在某一时刻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
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解答题-计算题
|
较难
(0.4)
【推荐2】等边
中,
于点
,点
为
边上一动点,连接
,点
关于直线
的对称点为点
,连接
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/0e2768bb-593f-48bc-a280-beeef96717fd.png?resizew=459)
(1)如图1,点
恰好落在
的延长线上,则求
______
;
(2)过点
作
交
于点
,连接
交
于点
.
①如图2,试判断线段
、
和
之间的数量关系,并说明理由:
②如图3,直线
交
于点
,连接
点运动的过程中.当
取最小值时,请直接写出线段
的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e1ddf6c0c55a38dcb6750bba4e37341.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cae003af00d9a4a443168a520360f7a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/0e2768bb-593f-48bc-a280-beeef96717fd.png?resizew=459)
(1)如图1,点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/826c728050e3378921442ace20269ef6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b753dbb5a670dd4f5e23bb919e44dda2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83873a9d782f2588c5eedbfe73f9bc2f.png)
(2)过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afedac49ce38f25e0a73e579133afe5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91f3956f008cc29ca4bae44a087d5427.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
①如图2,试判断线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
②如图3,直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91f3956f008cc29ca4bae44a087d5427.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/826c728050e3378921442ace20269ef6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74560a1dfdf34011663a5f4252eb7fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/767dbeffdf9182a42cce2a544a9f09cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐1】如图①,在△ABC中,∠A=90°,AB=AC=
+1,BC=2+
,点D、E分别在边AB、AC上,且AD=AE=1,DE=
.现将△ADE绕点A顺时针方向旋转,旋转角为
(0°<
<180°).如图②,连接CE、BD、CD.
(1)如图②,求证:CE=BD;
(2)利用备用图进行探究,在旋转的过程中CE所在的直线能否垂直平分BD?如果能,请猜想α的度数,画出图形,并将你的猜想作为条件,给出证明;如果不能,请说明理由;
(3)在旋转的过程中,当△BCD的面积最大时,
= °.(直接写出答案即可)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
(1)如图②,求证:CE=BD;
(2)利用备用图进行探究,在旋转的过程中CE所在的直线能否垂直平分BD?如果能,请猜想α的度数,画出图形,并将你的猜想作为条件,给出证明;如果不能,请说明理由;
(3)在旋转的过程中,当△BCD的面积最大时,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://img.xkw.com/dksih/QBM/2021/11/9/2847577948946432/2848133452414976/STEM/eb4c3fc1-1b0f-48a4-9dfd-628eadaee99f.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】在 Rt
中,
,
,点
为射线
上一点,连接
,过点
作线段
的垂线
,在直线
上,分别在点
的两侧截取与线段
相等的线段
和
,连接
,
.
(1)当点
在线段
上时(点
不与点
,
重合),如图1,
①请你将图形补充完整;
②线段
,
所在直线的位置关系为 ,线段
,
的数量关系为 ;
![](https://img.xkw.com/dksih/QBM/2019/11/8/2329475672522752/2330392080113664/STEM/e41c488186b64626a22ffd1822f30378.png?resizew=221)
(2)当点
在线段
的延长线上时,如图2,
①请你将图形补充完整;
②在(1)中②问的结论是否仍然成立?如果成立请进行证明,如果不成立,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6247d0dae1512a44ce73efbc42ac47cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a355958abf7dc0f2eb949584cb87907b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6b41d4070854edfaa24071137b314cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8120f2eeb724c756b5f84a14c6df527.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c4eccda4edcee29a5f15609e85106df.png)
(1)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
①请你将图形补充完整;
②线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c4eccda4edcee29a5f15609e85106df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c4eccda4edcee29a5f15609e85106df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://img.xkw.com/dksih/QBM/2019/11/8/2329475672522752/2330392080113664/STEM/e41c488186b64626a22ffd1822f30378.png?resizew=221)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
①请你将图形补充完整;
②在(1)中②问的结论是否仍然成立?如果成立请进行证明,如果不成立,请说明理由.
![](https://img.xkw.com/dksih/QBM/2019/11/8/2329475672522752/2330392080113664/STEM/828d52f0ba2b4680a99c9a04851c6c73.png?resizew=255)
您最近一年使用:0次