1 . 如图,在矩形
中,E是
边的中点,
,垂足为F,连接
,分析下列四个结论,①
,②
;③
;④
.其中正确的结论有( )
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/6/41c4556c-6572-4ef2-b148-e336621ec7a2.png?resizew=155)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d320f180419175d75eebc618cc458b39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5d2579e4f5268621f9cb5534c5ce8b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7611391918a3aec67fe832b38225891a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2e94399c4924cf2a862737a2825fe4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5b7b242d50273608e50140c2451c76.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/6/41c4556c-6572-4ef2-b148-e336621ec7a2.png?resizew=155)
A.4个 | B.3个 | C.2个 | D.1个 |
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2 . 【操作】
如图1,
是等腰直角三角形,
,
是其内部的一点,连接
.将
绕点
顺时针旋转90°得到
,连接
、
,作直线
交
于点
.
(1)求证:
;
(2)设
与
交于点
,求
的度数;
【探究】
(3)如图2,连接图1中的
,分别取
、
、
的中点
、
、
,作
.若
,求
的周长.
如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/15/3bcf4455-0438-4862-a340-23e1c5d02c16.jpg?resizew=280)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb8f2384b0b39aa71d1c64dab94fcd8.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13a2e6494cf8d2dff0746a9bb72cef43.png)
【探究】
(3)如图2,连接图1中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d23b488f961d9fde37feb7f5c497c0d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3032820a0d2d50d9143e7923f5936ddf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d23b488f961d9fde37feb7f5c497c0d9.png)
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解题方法
3 . (1)观察猜想:如图①,在
和
中,
,
,
,连接
,点
是
的中点,连接
、
,当点
、
、
三点共线时,线段
与线段
的数量关系是_________,位置关系是_________.
(2)探究证明:在(1)的条件下,将
绕点
顺时针旋转至图②位置时,(1)中的结论是否仍然成立?如果成立,请你就图②的情形进行证明;如果不成立,请说明理由.
(3)拓展延伸:如图③,在
和
中,
,
,
,连接
,点
是
的中点,连结
、
,将
绕点
在平面内自由旋转,请直接写出
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eddf629bfb2d7b9daea6f2c1553360af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e47d2d1ca5d4ea1c6cd1a0645fd1a30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a7ce2e389c0db029894b28c47225c34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3570a95f68349fcd9417fcda62e78e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38ac49caae8e3b8869d19beeff98966e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
(2)探究证明:在(1)的条件下,将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e47d2d1ca5d4ea1c6cd1a0645fd1a30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(3)拓展延伸:如图③,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eddf629bfb2d7b9daea6f2c1553360af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e47d2d1ca5d4ea1c6cd1a0645fd1a30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a7ce2e389c0db029894b28c47225c34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cceebd6fb7cafea3590e67040d74136.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bcb9ec57d28a9d3aed7f8e67d98bbb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c15514bc735fe4b744672edefe00009c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/27/004b8035-f7d3-442c-8a9d-b23141e9b334.png?resizew=505)
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4 . 小明在一次数学活动中发现,可以用一刀将下图所示的直角三角形ABC裁剪为两部分,然后将这两部分拼成一个矩形.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/17/c947a2a3-c277-43a8-9caf-d28e6e25f57e.png?resizew=608)
(1)请你直接在图1上画出小明的方法,并简要说明画法;
(2)在小明研究的基础上,小亮又发现对任意三角形而言只要两刀将其裁剪后,也可以拼成一个矩形,并且裁剪的方法不同,所拼成的矩形也不同.
①请你在图2中画出两种不同的裁剪拼接方法;
②若三角形三边BC、AC、AB分别为
,试说明当所拼成矩形一边分别为BC、AC、AB边时,哪一种拼法的周长最大?
(3)能否将一个任意四边形裁剪后拼成一个矩形?若能,最少裁几刀?画图说明即可.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/17/c947a2a3-c277-43a8-9caf-d28e6e25f57e.png?resizew=608)
(1)请你直接在图1上画出小明的方法,并简要说明画法;
(2)在小明研究的基础上,小亮又发现对任意三角形而言只要两刀将其裁剪后,也可以拼成一个矩形,并且裁剪的方法不同,所拼成的矩形也不同.
①请你在图2中画出两种不同的裁剪拼接方法;
②若三角形三边BC、AC、AB分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce613eaa5df46a50174085ef5d1087fb.png)
(3)能否将一个任意四边形裁剪后拼成一个矩形?若能,最少裁几刀?画图说明即可.
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5 . 点E为正方形ABCD的AB边上的一个动点,AB=3,如图1,将正方形ABCD对折,使点A与点B重合,点C与点D重合,折痕为MN.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/14/6cacdf25-8b14-4050-82a4-6c657a07cea8.png?resizew=434)
思考探索
(1)如图2,将正方形ABCD展平后沿过点C的直线CE折叠,使点B的对应点B′落在MN上,折痕为EC.
①点B'在以点E为圆心, 的长为半径的圆上;
②B'M=______;
拓展延伸
(2)当AB=3AE时,正方形ABCD沿过点E的直线l(不过点B)折叠后,点B的对应点B'落在正方形ABCD内部或边上,连接AB'.
①△ABB'面积的最大值为______;
②点P为AE的中点,点Q在AB'上,连接PQ,若∠AQP=∠AB'E、求B'C+2PQ的最小值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/14/6cacdf25-8b14-4050-82a4-6c657a07cea8.png?resizew=434)
思考探索
(1)如图2,将正方形ABCD展平后沿过点C的直线CE折叠,使点B的对应点B′落在MN上,折痕为EC.
①点B'在以点E为圆心, 的长为半径的圆上;
②B'M=______;
拓展延伸
(2)当AB=3AE时,正方形ABCD沿过点E的直线l(不过点B)折叠后,点B的对应点B'落在正方形ABCD内部或边上,连接AB'.
①△ABB'面积的最大值为______;
②点P为AE的中点,点Q在AB'上,连接PQ,若∠AQP=∠AB'E、求B'C+2PQ的最小值.
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2022-07-04更新
|
397次组卷
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5卷引用:2022年陕西省延安市新区中考数学二模试题
2022年陕西省延安市新区中考数学二模试题(已下线)专题24.38 圆中的几何模型-隐形圆专题(专项练习)-2022-2023学年九年级数学上册基础知识专项讲练(人教版)(已下线)专题3.41 圆中的几何模型(隐形圆专题)(专项练习)-2022-2023学年九年级数学下册基础知识专项讲练(北师大版)2023年河南省鹤壁市中考一模数学试题(已下线)2023年河南省一模(几何综合1)
解题方法
6 . 已知正方形ABCD中,点E,F分别在边CD,BC上,连接AE,DF.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/af05918e-284a-4958-a142-b85bada774d2.png?resizew=405)
(1)若E为CD的中点,
于点O.
①如图1,求证:
;
②如图2,连接OC,求
的值;
(2)如图3,若
,
,则
的最小值为_________(直接写出结果).
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/af05918e-284a-4958-a142-b85bada774d2.png?resizew=405)
(1)若E为CD的中点,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2615265e2d0d04b85299b54c3950a30b.png)
①如图1,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cf5b86308e9f777a6611503ba8d0e9e.png)
②如图2,连接OC,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50bce935f274c98267d90440266cbed7.png)
(2)如图3,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cfebeceba5791f21e3b9fac7b4be681.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86d1125b47dec1c5e93143ee59ad862a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bc8780c1ab6931b25c3e54d5cb00231.png)
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2021-08-12更新
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5卷引用:陕西省西安滨河学校2022-2023学年八年级上学期第一次月考数学试卷
名校
7 . 如图,点E是平行四边形ABCD对角线AC上一点,点F在BE延长线上,且EF=BE,EF与CD交于点G.
(1)求证:DF∥AC;
(2)连接DE、CF,若2AB=BF,且G恰好是CD的中点,求证:四边形CFDE是矩形;
(3)在(2)的条件下,若四边形CFDE是正方形,且BC=80,求AB的长.
(1)求证:DF∥AC;
(2)连接DE、CF,若2AB=BF,且G恰好是CD的中点,求证:四边形CFDE是矩形;
(3)在(2)的条件下,若四边形CFDE是正方形,且BC=80,求AB的长.
![](https://img.xkw.com/dksih/QBM/2021/7/23/2770234855374848/2776325382668288/STEM/d0a856dc30c34bf3bf21072b7eb64f67.png?resizew=190)
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2021-07-31更新
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7卷引用:陕西省西安市汇文中学2021年九年级秋季数学开学考