1 . 在矩形
中,点O是对角线
,
的交点,直角
的顶点p与O重合,
,
分别与
,
边相交于E,F,连接
,
(
为常数).
(1)发现问题:如图1,若
,猜想
.
(2)类比探究:如图2,
,探究线段
,
之间的数量关系,并说明理由.
(3)拓展运用:如图3,在(2)的条件下,若
,
,
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfa70e7c9ef8b856b494d370b7d76482.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cad4595d5352b2884568a59d8d766a4.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/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57fdde5c60611ad99eac513a724492da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/23/63b9b481-d458-4163-8e24-6910c709658b.png?resizew=407)
(1)发现问题:如图1,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5095a28bb1b91bf6bed9e2cfbd76bb18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/296e84ad7592188c975912ba17af0ee3.png)
(2)类比探究:如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04c525393775354325cbf7839366ca50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cad4595d5352b2884568a59d8d766a4.png)
(3)拓展运用:如图3,在(2)的条件下,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb6abd4e67785049f8ea82d2309f49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9173b446b8ff3ec5506540f277d93a15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76ef25427331ab3c7190da269561a56a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
您最近一年使用:0次
2 . 三个等角的顶点在同一条直线上,称一线三等角模型(角度有锐角、直角、钝角,若为直角,则又称一线三垂直模型).解决此模型问题的一般方法是利用三等角关系找全等或相似三角形所需角的相等条件,利用全等或相似三角形解决问题.
如图1,在四边形
中,点
为
上一点,
,求证:
.
【思考探究】
(2)如图2,在四边形
中,点
为
上一点,当
时,上述结论是否依然成立?说明理由.
【拓展延伸】
(3)请利用(1)(2)获得的经验解决问题:
如图3,在
中,
,
,以点
为直角顶点作等腰
,点
在
上,点
在
上,点
在
上,且
,若
,求
的长.
如图1,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/7502d2b89b731a7c11faa97815d46d87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7c4bc1c164e8dd6747cf998b237ef90.png)
【思考探究】
(2)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/500244f771b0e34b7fd1970e6757e5d5.png)
【拓展延伸】
(3)请利用(1)(2)获得的经验解决问题:
如图3,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080ca48cd27d4bf9d9ef084b558fc17a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7099026716ee1821dd7d9f157dc055f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40e7ba6e267dde1a65a98f9f36b585ce.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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a02a4bbef957f179f55c28b37c64ce37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4307209e1e5cad88fc1b8163858688ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
您最近一年使用:0次
3 . 类比、转化、从特殊到一般等思想方法,在数学学习和研究中经常用到,如下是一个案例,请补充完整.
原题:如图
,在平行四边形
中,点
是
的中点,点
是线段
上一点,
的延长线交射线
于点
.若
,求
的值.
(1)尝试探究
在图
中,过点
作
交
于点
,则
______,
______.
(2)类比延伸
如图
,在原题的条件下,若
,求
的值
用含有
的代数式表示
.试写出解答过程.
(3)拓展迁移
如图
,在四边形
中,
,点
是
的延长线上的一点,
和
相交于点
若
,
,
,则
的值是______
用含
、
的代数式表示
.
原题:如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.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/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c022e2d7244ef61eb4673c8d4108d30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f803c907aa8d31a9359f24405990fc92.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/8/14e7afad-9adf-4e7b-85b3-9082ab37ceca.png?resizew=421)
(1)尝试探究
在图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44d6321e6de60f4e62964c83759def91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06e322e0c87479bba874db9ae9ba36b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e17208df62de9833634fa97bae547ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/610e48df11f5f3697227ed771b12da11.png)
(2)类比延伸
如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0710741279bc12073a2b24d10091136d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f803c907aa8d31a9359f24405990fc92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd995178601c2ad7b40f973d268c7bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
(3)拓展迁移
如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fe2f6543e06a25493855fbbc648be6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.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/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5704eac867e33aaefd43da48b0f222f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8512c09a56d86987b45d4701d28fd89f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d705409bc9066d65bbbf89091397b3e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf73f545ecbe7ce232c0389484cec5d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33ec395fe7a4bc51dac28c37085fabcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd995178601c2ad7b40f973d268c7bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
您最近一年使用:0次
名校
4 . 课本再现:
(1)在图1中,一块材料的形状是锐角三角形
,边
,高
.把它加工成正方形零件,使正方形的一边在
上,其余两个顶点分别在
上,求这个正方形的边长.
变式探究:
(2)如图2,若一块三角形材料可以加工成3个相同大小的正方形零件,请你探究
与
的数量关系,并说明理由.
拓展延伸:
(3)如图3,若一块三角形材料可以加工成4个相同大小的正方形零件,且
,请你探究
的值.
(4)如图4,若一块三角形材料用同样的方式,可以加工成
个相同大小的正方形零件,设每个正方形的边长为a,则
.(用含a,n的代数式表示,直接写出结果)
(1)在图1中,一块材料的形状是锐角三角形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/804cd8843150965cb8a0613ff243b9a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbd592ad6bffa2ae5c10da819469733b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dec2ca6438c82b43f746057d8129885.png)
变式探究:
(2)如图2,若一块三角形材料可以加工成3个相同大小的正方形零件,请你探究
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
拓展延伸:
(3)如图3,若一块三角形材料可以加工成4个相同大小的正方形零件,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d3c9ce32b721995f355eea411340e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/882f6fe6d8d03466a1330717c983c4f0.png)
(4)如图4,若一块三角形材料用同样的方式,可以加工成
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df98a2c4252e3b4e0397b4537da03edd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16ca90e8a784f990c4097eec9219908d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/25/a778be5a-2189-475e-b34e-7e053277bec7.png?resizew=433)
您最近一年使用:0次
2024-02-25更新
|
79次组卷
|
2卷引用:江西省南昌市外国语学校2023-2024学年九年级上学期期末数学试题
5 . 在正方形
中,
,点
、
分别是边
、
上的点,连结
,将正方形
沿
翻折,使点
的对称点
落在边
上,点
的对称点为点
,
交边
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/10/0ce3b2db-9a9a-443c-8cd2-2bf1e97dfb52.png?resizew=458)
【探究】如图①,若点
是边
中点,求
的值.
【应用】(1)如图②,若
,则
的值为______.
(2)如图③,若
,则
的值为______.
【拓展】若
,则
的值为______.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d42e97eee705d164e6ac6de9ecd6d1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4505508b3e36db64a207dcdaf8eb22dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/10/0ce3b2db-9a9a-443c-8cd2-2bf1e97dfb52.png?resizew=458)
【探究】如图①,若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e163ba26447f8edfe522252eee1aaf.png)
【应用】(1)如图②,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c3eaf4e53058ea12e51c27c71223285.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e163ba26447f8edfe522252eee1aaf.png)
(2)如图③,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d92bef5853399c499bc90286f116ab1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e163ba26447f8edfe522252eee1aaf.png)
【拓展】若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf1bd3fe17457a32f36dc2b0bdef56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e163ba26447f8edfe522252eee1aaf.png)
您最近一年使用:0次
6 . 在
中,
,在
中,
,
,连接
,
,垂足为N,
,垂足为M.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/94ddc6ee-8543-489c-b638-898d5dd41912.png?resizew=372)
(1)观察猜想
图①中,点D,E分别在
,
上时,
的值为___________;
的值为___________.
(2)探究证明
如图②,将
绕点A顺时针旋转,旋转角为
,连接
,
,判断问题(1)中的数量关系是否仍然存在,并证明;
(3)拓展延伸
在
旋转的过程中,设直线
与
相交于点F,若
,
,请直接写出线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42798067d911f96e5784cb138319c907.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40975f7553d8cfa57951b568bae9c464.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ab1ad841a5ac6adb1dcc1c3b0bfa799.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b7361323e17eb0167cf280c210d7b4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce97d5dfa5975f40b05902d95c75e5ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ab7c7e6678695363cb5f4319e68bc52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc91d24995f16acfb67b775805c9821a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/94ddc6ee-8543-489c-b638-898d5dd41912.png?resizew=372)
(1)观察猜想
图①中,点D,E分别在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9af91834644b94e1b023b33e15a0644.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/393f9e541aada43c810ded7b3ab77a47.png)
(2)探究证明
如图②,将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c54ce139ae5d63691cac8a1ce5bbfe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(3)拓展延伸
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3657f0b0446428b86d98757cf55ea418.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
您最近一年使用:0次
7 . 如图,已知
,M为边
上一动点,
,D为边
上一动点,
,
交
于点N.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/f283cd8c-b5c8-424c-9b77-f18c6ac93c18.png?resizew=145)
(1)【问题提出】三角形的三条中线会相交于一点,这一点就叫做三角形的重心,重心有很多美妙的性质,请大家探究以下问题
若
,则
______(直接写出结果)
(2)【问题探究】若
,猜想
与n存在怎样的数量关系?并证明你的结论
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/cb845f04-fdcf-41f6-a972-78c12d99be0a.png?resizew=144)
(3)【问题拓展】若
,
,则
______(直接写出结果)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98caa861545702b245f784763e2a8fb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8bcdf7b87d420ca5d62a9a7be622c00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/f283cd8c-b5c8-424c-9b77-f18c6ac93c18.png?resizew=145)
(1)【问题提出】三角形的三条中线会相交于一点,这一点就叫做三角形的重心,重心有很多美妙的性质,请大家探究以下问题
若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/821fa0301d20076ad2e541f8c4a86231.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c708e6fb5afa56cce4c02fdc2902a92e.png)
(2)【问题探究】若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf0086b054ef120408acac806a1b1318.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43dbaba6a18402f0010e7dca9e90d44a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/cb845f04-fdcf-41f6-a972-78c12d99be0a.png?resizew=144)
(3)【问题拓展】若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf0086b054ef120408acac806a1b1318.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc2d3df37e73a8abea815f37dbb3fff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81489a2f2e16926e2bd2db78da4e39af.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/5ef28070-a768-48c0-ae9c-b98c28511c5c.png?resizew=145)
您最近一年使用:0次
8 . 【问题呈现】
(1)如图1,
和
都是等边三角形,连接
,则
与
的数量关系为______;
【类比探究】
(2)如图2,
和
都是等腰直角三角形,
,连接
,则
______;
【拓展提升】
(3)如图3,
和
都是直角三角形,
,连接
,
①求
的值;
②延长
交
于点
,交
于点
,求
的度数.
(1)如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a03841966d8142fa4a4aed023e37931.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
【类比探究】
(2)如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21c2425db34d83dbe44f3ee3d2c5439b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a03841966d8142fa4a4aed023e37931.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d698ee39cd00a9b6384e0c4897a055a.png)
【拓展提升】
(3)如图3,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae0557ee20e6b556b415fc60611d5b40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a03841966d8142fa4a4aed023e37931.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9af91834644b94e1b023b33e15a0644.png)
②延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.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/77282d5b97a60264cf15fb74b48e4b59.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/27/7141d4c2-0318-4c34-b74f-48b9fd697523.png?resizew=355)
您最近一年使用:0次
9 . 已知点
为
和
的公共顶点,将
绕点
顺时针旋转
,连接
.
和
均为等边三角形,则线段
与线段
的数量关系是______;
(2)类比探究:如图2所示,若
,其他条件不变,请写出线段
与线段
的数量关系,并说明理由;
(3)拓展应用:如图3所示,若
,
,
,
,当点
三点共线时,请直接写出
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/335c1d4db7d83b1271c2d6ff87a24b6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06e8d80f6159c7b21b9238a0696a0da4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
(2)类比探究:如图2所示,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65c8f57eb7444878e07bf4958ecfb2ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
(3)拓展应用:如图3所示,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/771fdf6c640e2368b2fc37486a9eaee9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686171942bd7698035016c732db43b63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/093eeec1ce84c6339c16201712e7d32b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2fb188915d2e3d7bfd633fa18221b07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
您最近一年使用:0次
2024-02-09更新
|
71次组卷
|
2卷引用:河南省鹤壁市2023-2024学年九年级上学期1月期末数学试题
10 . 如图1,在
中,
,
,点
分别是边
的中点,连接
将
绕点C按顺时针方向旋转,记旋转角为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/29/66446f2a-5175-4466-8eba-3bf15737152d.png?resizew=384)
(1)问题发现:
当
时,
;
当
时,
(2)拓展探究:试判断:当
时,
的大小有无变化?请仅就图2的情况给出证明.
(3)问题解决:当
旋转至
三点共线时,直接写出线段
的长.
![](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/ee69e271b5823faa6ac1f0f90c04d1c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3648c864f9f58da1dbb166fee84cfeaf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fa49835cb36d11ba406fa8cabbecd69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a5d48ad0b2862e276d3f19c4437a8fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f850c705372b8a85489505da53239fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e514bc1761deff47d27c1909c1906ab4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/29/66446f2a-5175-4466-8eba-3bf15737152d.png?resizew=384)
(1)问题发现:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1c9ae241fd78126274c65e17990c88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e7e8c4e8015bc1a44a89460e1dc0d63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2ab4209d1546277a66e3a2ddadbae13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c650fe55b7603f106c53ca2423451c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddd284be60584dfae454b1a125468947.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37cd58a41e2a35369b960b473a97a8c4.png)
(2)拓展探究:试判断:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcfbe55f659e4b597bb81680b20db4c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e16b888776c7327ccc98c7c9adf672d.png)
(3)问题解决:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f850c705372b8a85489505da53239fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92d38160532e95012fdfbc2a1be264b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
您最近一年使用:0次