1 . 问题提出
在综合与实践课上,某数学研究小组提出了这样一个问题:如图1,在边长为4的正方形
的中心作直角
,
的两边分别与正方形
的边
,
交于点E,F(点E与点B,C不重合),将
绕点O旋转.在旋转过程中,四边形
的面积会发生变化吗?
爱思考的浩浩和小航分别探究出了如下两种解题思路.
浩浩:如图a,充分利用正方形对角线垂直、相等且互相平分等性质,证明了
,则
,
.这样,就实现了四边形
的面积向
面积的转化.
小航:如图b,考虑到正方形对角线的特征,过点O分别作
于点G,
于点H,证明
,从而将四边形
的面积转化成了小正方形
的面积.
__________;
__________.
类比探究
(2)①如图⒉,在矩形
中,
,
,O是边
的中点,
,点E在
上,点F在
上,则
__________.
②如图3,将问题中的正方形
改为菱形
,且
,当
时,其他条件不变,四边形
的面积还是一个定值吗?若是,请求出四边形
的面积;若不是,请说明理由.
拓展延伸
(3)如图4,在四边形
中,
,
,
,
,
是
的平分线,求四边形
的面积.
在综合与实践课上,某数学研究小组提出了这样一个问题:如图1,在边长为4的正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b2557547eecdc826b8282058802d217.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b2557547eecdc826b8282058802d217.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b2557547eecdc826b8282058802d217.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
爱思考的浩浩和小航分别探究出了如下两种解题思路.
浩浩:如图a,充分利用正方形对角线垂直、相等且互相平分等性质,证明了
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8e9b8559813d320d0439aeb6a7fb32b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29469ffc253990fb7036224c0807eabc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11cf9c64341fe7583043e5e721a9f4c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4807ca16360c0cca436e59d4be98f626.png)
小航:如图b,考虑到正方形对角线的特征,过点O分别作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbdaf6769ca790186718cc60c7b89ba6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27acaeba896dd1a4a221151ffa464848.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18f651cafe4e7eabefc7d9db3364a46e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/576f3737faa25501719f13e7495d7ef3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8678190eb56dda0061c60fe08bc2a86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a12ffa9b9913fb53f8f50a420df7373.png)
类比探究
(2)①如图⒉,在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/267ace52b64e1e7dfc5211e033255b7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/319ff9f648fedec284a11a9761cb6183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f273e22d58841c1a850d4b96cebbcaf9.png)
②如图3,将问题中的正方形
![](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/6e901c430af74f7bbce43364bd4f2e47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee480d748f36c1b43e941384dd41f13e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
拓展延伸
(3)如图4,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b8b709a173120436dac669c74b927d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16ed75e65e7374c38ffb1f75259a8beb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b0382c28547d3834ca71f3f0677695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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2 . 已知,在
中,
,
,点
为边
上一个动点,以
为边作其右侧作等边
.
(1)如图1,线段
与线段
之间的数量关系为__________;
(2)如图2,过点
作
于点
.求证:点
是
的中点;
(3)若
.
①如图3,当点
是
的中点时,过点
作
于点
.求
的长;
②当点
从点
运动到点
,则点
所经过的路径长__________(直接写出结果).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60d9142db4dd2ef151bf3d4a63afb61e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392b9e1a179a6676362679354a9e7e51.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/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/10/48fa80cb-54fe-43c0-a999-29895284a0c1.png?resizew=399)
(1)如图1,线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(2)如图2,过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8de4a54cc7818be87a239f6de5f5d05b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
①如图3,当点
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8c13ab7f17263c4e6163d960f1c5060.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e55e398e8520d8a36fb5a625a085b8.png)
②当点
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
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3 . 如图,
为线段
上一动点(不与点
,
重合),在
同侧分别作等边三角形
和等边三角形
,
与
交于点
,
与
交于点
,
与
交于点
,连接
.下列五个结论:①
;②
;③
;④
;⑤
是等边三角形.其中正确结论的个数是( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/787ac5e13622afab5e9f8603afe42356.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68251f6ce06168cfb89fe164ecf104ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0213c5787a5a6b38d11bceca5567f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0213c5787a5a6b38d11bceca5567f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e430f13f42cf2d44aa0f0e20b959684f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c503e29373e8d87134bdb46bd3912910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60e5c088a90d0f4052fc92dd9b7addf9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7341c7d3b742bf451457145206782711.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6b29ebc71207e74f6a615a3018d7993.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e87b2f781cafa7989d81f9bf8c42b150.png)
A.2个 | B.3个 | C.4个 | D.5个 |
您最近一年使用:0次
2023-09-22更新
|
437次组卷
|
3卷引用:江西省九江市永修县第三中学2023-2024学年期八年级下学期期中数学试题
4 . 在一堂数学实践课上,赵老师给出了下列问题:
![](https://img.xkw.com/dksih/QBM/2023/1/15/3153178131079168/3154561169833984/STEM/6703a949fa744ca08e88696b32f882af.png?resizew=436)
(1)【提出问题】如图1,在
中,E是
的中点,P是
的中点,就称
是
的“双中线”,
.则
______.
(2)【探究规律】在图2中,E是正方形
一边上的中点,P是
上的中点,则称
是正方形
的“双中线”,若
.则
的长为______(按图示辅助线求解);
(3)在图3中,
是矩形
的“双中线”,若
,请仿照(2)中的方法求出
的长,并说明理由;
(4)【拓展应用】在图4中,
是平行四边形
的“双中线”,若
.求出
的周长,并说明理由?
![](https://img.xkw.com/dksih/QBM/2023/1/15/3153178131079168/3154561169833984/STEM/6703a949fa744ca08e88696b32f882af.png?resizew=436)
(1)【提出问题】如图1,在
![](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/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82f73b415f8e1d38f900aee9230a23c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc2ddabf078c1b683b067eb1aee1969.png)
(2)【探究规律】在图2中,E是正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
(3)在图3中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b809a18908a1ce2630296af9862dc141.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
(4)【拓展应用】在图4中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11395075cde11da2ae5a590f44e552bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a855335176fc36a15017f50a8561348.png)
您最近一年使用:0次
2023-01-17更新
|
126次组卷
|
2卷引用:江西省抚州市临川区第四中学2023-2024学年九年级上学期月考数学试题