1 . 已知,和
都是等腰直角三角形,
是
的中点,连接
.
(1)如图1,点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a65183d238c9bc2be73770717d890683.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
(2)将图1中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c78bdc0901946ce47761b697fe1d3c09.png)
①在图2中,按要求补全图形,并证明;
②连接,交
于点
.判断线段
与
的数量关系,并证明.
(3)将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99a1465fd3835e3907212e120665656c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53f0a866c83f0445daae94f21394be39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ac3aad3d7b8fe0483577002ea3024ef.png)
您最近一年使用:0次
2024-03-17更新
|
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2卷引用:2023年江苏省南通市启东市中考二模数学模拟试题
2024九年级下·浙江·专题练习
2 . 阅读下面材料:
我遇到这样一个问题:如图1,在正方形
中,点E、F分别为
、
边上的点,
,连接
,求证:
.我是这样思考的:要想解决这个问题,首先应想办法将这些分散的线段集中到同一条线段上.他先后尝试了平移、翻折、旋转的方法,发现通过旋转可以解决此问题.他的方法是将
绕点A顺时针旋转
得到
(如图2),此时
即是
.
的度数是 .
参考我得到的结论和思考问题的方法,解决下列问题:
(1)如图3,在直角梯形
中,
,
,
,E是
上一点,若
,
,求
的长度.
(2)如图4,
中,
,
,以
为边作正方形
,连接
.当
时,线段
有最大值,并求出
的最大值.
我遇到这样一个问题:如图1,在正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/192155e6a3aade305b76b1eb7c75e30c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a99627df7b1a88b9bf3dda20390d245.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bc727c642cbc2181476b7dd8eca471e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0e57a13c665af88f326c9890072bf73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4eef107fa9d4cedabdf5906c627cce5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f9f70b2bf8747fb27c7ca1ae7cdea4.png)
参考我得到的结论和思考问题的方法,解决下列问题:
(1)如图3,在直角梯形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3dfbc19352607a439c9a19d88dc3a33f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8cfd06965af6014208127f2880b476b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb5a38c27c3111dfd51b49de5b2e27fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2f12c8e863e2661cb4a4b4138b06101.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a19338598965bb3856cdd0236bbf694.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
(2)如图4,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07160f14b3b453bebb64cb2bf96dc85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d498a0467ff3c577a7ed175d7bffd885.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41db498f025052df2dbb1e50ab672675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
您最近一年使用:0次
2024-04-06更新
|
130次组卷
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5卷引用:专题07+平行四边形与特殊平行四边形2(5大易错点分析)-备战2024年中考数学考试易错题(浙江专用)
(已下线)专题07+平行四边形与特殊平行四边形2(5大易错点分析)-备战2024年中考数学考试易错题(浙江专用)2024年浙江省湖州市部分中学中考数学一模试题江苏省兴化市常青藤学校联盟2023-2024学年八年级下学期第1次月考数学试题(已下线)考题猜想9-1 中心对称图形-平行四边形(培优+拔尖,12种题型)-2023-2024学年八年级数学下学期期末考点大串讲(苏科版)福建省泉州科技中学2023-2024学年八年级下学期期中数学试题
解题方法
3 . 如图1,在等腰三角形
中,
,
,点
分别在边
上,
,连接
,点
分别为
的中点.
图
中,线段
与
的数量关系是_______,
的大小是_______;
(2)探究证明:
把
绕点
顺时针方向旋转到图
的位置,连接
,判断
的形状,试说明理由;
(3)拓展延伸:
把
绕点
在平面内自由旋转,若
,
,请直接写出
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f89deb952f57f4b3fa4887b098b7b91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3a51949f48ee8cf746851ba779b078e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5dc62e10004e73908091338362917da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d212c1709b8e72a055cf1b5381ef64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b48386aac017c768709a87cda4b7001b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99030fd6b3dc4a8e7f077a014e7fd8b4.png)
图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ffc7d1af9053b027cf9e726f5367.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4d7af76a3b1a09c6080fd5b39333dca.png)
(2)探究证明:
把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/132e8aefd4a28ece85814a1ed378a6c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d23b488f961d9fde37feb7f5c497c0d9.png)
(3)拓展延伸:
把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4aca5534bce25acaeb7379deed8f8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d23b488f961d9fde37feb7f5c497c0d9.png)
您最近一年使用:0次
2024-04-04更新
|
414次组卷
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7卷引用:广东省深圳市南山区部分学校 2022-2023学年九年级下学期教学质量第一次调研数学试题
广东省深圳市南山区部分学校 2022-2023学年九年级下学期教学质量第一次调研数学试题2024年广东省深圳市 南山外语中学、南山外语第二中学中考一模数学试题2024年湖北省恩施市熊家岩初级中学中考一模数学试题(已下线)抢分秘籍11 几何图形中求线段,线段和,面积等最值问题(4题型)-备战2024年中考数学抢分秘籍(全国通用)(已下线)专题04 全等三角形模型训练(6类经典模型+优选提升)-【好题汇编】备战2023-2024学年八年级数学上学期期中真题分类汇编(人教版)(已下线)12.4(培优课)全等中的手拉手模型(题型精讲精练)-【题型分类精粹】2023-2024学年八年级数学上学期期中期末复习讲练系列【考点闯关】(人教版)(已下线)专题6.13 平行四边形(全章分层练习)(培优练)-2023-2024学年八年级数学下册基础知识专项突破讲与练(北师大版)
4 . 如图,在△ABC中,
,
,点
在边
上,
,
分别为
,
的中点,连接
.过点
作
的垂线,与
,
分别交于
,
两点.连接
,交
于点
.有以下判断:①
;②
,且
; ③当
时,
的面积为9;④
的最大值为
.其中正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f138deab9e5a4baaada287ed1a78df9.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/8455657dde27aabe6adb7b188e031c11.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/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c9385e2739b9bd2d1816e2efa881ff0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d28bf62863e1c57a81ff307c20f452ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c19438b486a70e3952347c101c8157d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56e5a8fdbfbdf25f6937b7a2d6a4cd95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1269ea1057c555e256a8ea4a717e0f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a920b809ab321817128e7ba83bab143.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f8d7da24c485205172663f40a52c962.png)
A.①③ | B.①③④ | C.①②④ | D.①②③④ |
您最近一年使用:0次
5 . 如图1,
与
均为等边三角形,将
绕点
逆时针旋转,旋转角为
(其中
),连接
,
,
是
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/31/24e0c63c-77a6-4a96-983b-1a99d0bad028.jpg?resizew=426)
(1)求证:
;
(2)如图2,连接
,当
的延长线经过点
时,请判断四边形
的形状,并说明理由;
(3)如图3,连接
,若
,在
绕点
旋转的过程中,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b96715995549e5e48494101570bb3bb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b96715995549e5e48494101570bb3bb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01e915c7310f3781887a1afb99dbf949.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/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4144763622b446911152e6a7ae740c74.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/31/24e0c63c-77a6-4a96-983b-1a99d0bad028.jpg?resizew=426)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82a6574405000dab3fec93b438aa2de0.png)
(2)如图2,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15a424b50eaeafa6f302ffd95476cb86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274a1e7040f3c9d3f7d6038c8ce6d886.png)
(3)如图3,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/714cc3707bba3bfdb56e251999be8592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b96715995549e5e48494101570bb3bb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
您最近一年使用:0次
6 . 已知四边形ABCD是菱形,
,点E是平面内任意一点,且
.连接
,线段
绕点A逆时针旋转到
,使
,连接
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3ba142708733e6bf5f65de71b9fbc59.png)
(2)如图2,
,连接
,当点E是
的中点时,求
的面积
(3)如图3,
,
,直线
与
相交于点G,连接
,直接写出在
旋转的过程中,
面积的最大值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eee296a7d9fba487f1485c61580196f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d7f21876f1112f7a64388f7719eb488.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79ff575e55857af133edb24c8e61504f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69babe5b1123f5e171c8845cbe4987c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef13221662e9fe0eba518e5fefffb4fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3ba142708733e6bf5f65de71b9fbc59.png)
(2)如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3182db896bc2462331796e2a6108363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3182db896bc2462331796e2a6108363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
(3)如图3,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1364213f546b37f8764ddcb59e36ae4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0213c5787a5a6b38d11bceca5567f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a679040c4d556723e482bacbab41356d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb11667abcb2759f301391b9850352be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c105d6ba18fbb0581fb982175e2eac9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcaecf08a22124a457128fb04c9c02bb.png)
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7 . 如图,正六边形ABCDEF的边长为3,G,H分别是CD,DE上两个动点,且CG=DH,BG,CH交于点P,点Q是AB的中点,连接PQ,则PQ长度的最大值为______ .
您最近一年使用:0次
名校
8 . 如图,在
中,
,
,以
为边在
的另一侧作
,点D为线段
(不含端点)上一点,在射线
上截取
,连接
、
、
,
与
交于点F,若
,
的最大值是______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fffa3d9c32da53b0ea0c338012ea20c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14b49022a6f55817b5d7e3ab443b5491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fabb884dc5f9609de491245463bbe9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4beb71587d214c3bc47e393149177c5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e883f81c66ceef54d2d0556a68ed585.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa80cfd38f59e5cbbb30628d03113689.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a6c6e7c025362c46a64a8956761f08e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1a9c6a736e6eac98a676fa3232db5a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a6c6e7c025362c46a64a8956761f08e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54275b7e571660d0a9e0370fbfe5050b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8120f2eeb724c756b5f84a14c6df527.png)
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2024九年级下·全国·专题练习
9 . 如图所示,已知
,
,
,点D和点E分别是
和
边上的动点,满足
,连接
,点F是
的中点,则
的最大值为 _________________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/847803f215e1d8e69392df42c6473741.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ad037d6d1bddf8930944fd93b5a551b.png)
![](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/4fe386f7c622c15a7f059590482fb081.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cd2cc30a50994ac39a5059e02c16272.png)
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10 . 在
中,
,
,
为平面内的一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/19/f861ec63-94b1-4517-83d0-b4b106051479.png?resizew=374)
(1)如图1,当点
在边
上时,
,且
,求
的长;
(2)如图2,当点
在
的外部,且满足
,求证:
;
(3)如图3,
,当
、
分别为
、
的中点时,把
绕点
顺时针旋转,设旋转角为
,直线
与
的交点为
,连接
,直接写出旋转中
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/19/f861ec63-94b1-4517-83d0-b4b106051479.png?resizew=374)
(1)如图1,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/714cc3707bba3bfdb56e251999be8592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e4dbea6a5faecdd8f6c06cf9fd43a90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(2)如图2,当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3ec8ae1589b3dba50bc54c19e4786f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf0cca06ba3a9eaf080977c32735b852.png)
(3)如图3,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](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/63b43490ca09467a4c8cd8cfe91c94e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5583e020f88e63208bdfb464d3813ce4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
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