1 . 在学习全等三角形的知识时,数学兴趣小组发现这样一个模型∶它是由两个共顶点且顶角相等的等腰三角形构成,在相对位置变化的同时,始终存在一对全等三角形.通过查询资料,他们得知这种模型称为“手拉手模型”.如图① ,在
中,
,点D,E分别在
边上,
,连接
,M是
的中点,连接
.
请直接写出
与
的数量关系和位置关系;
(2)类比探究
将图① 中
绕点C逆时针旋转到图② 的位置,判断(1)中的结论是否仍然成立,若成立,请写出证明过程;若不成立,请说明理由;
(3)解决问题
若
,将图① 中的
绕点C逆时针旋转一周时,请直接写出
的最大值与最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f76899b3a0bfbbdae7cb1148ad4bf018.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76ddaedf96d5c1a550fe54ad20ad1f0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e675a92cad72c65aa4071b9d9e226090.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5eaffcd2070bfcb1955e2cab66c26c06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97d8b9c22198b4aaef495b9a449cfb68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
请直接写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
(2)类比探究
将图① 中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a0acc93490a6a784eb62201d93dd93d.png)
(3)解决问题
若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5d77805882d13f1f7d595dfcbaff9df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a0acc93490a6a784eb62201d93dd93d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
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2 . 如图,在等腰
中,
,
,
为线段
上一点,以
为半径作
交
于点
.连接
、
,线段
、
、
的中点分别为D、M、N.
(1)试探究
是什么特殊三角形,说明理由.
(2)将
绕点O逆时针方向旋转到如图的位置,其结论是否仍然成立,并证明结论.
(3)设
,把
绕点O在平面内自由旋转,求
的面积y的最大值与最小值的差(用x表示).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b352fa3e781df195ceccca90c3932a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b46203728bb089612d0ae92a8a939085.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3825ccc273ef9a672a606432d165b866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/22/571801dc-d5d6-4f43-9f41-ac1df64d7313.png?resizew=189)
(1)试探究
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/999c42a021bdc576f097246b9e64d986.png)
(2)将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea1f0417d8269f01d8e0bc1a8756e2ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/22/bf7a50dc-c0fa-4c9f-ad23-7d109ead2723.png?resizew=176)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d70b18ec2efde60bacdbadbf6c9af8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea1f0417d8269f01d8e0bc1a8756e2ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/999c42a021bdc576f097246b9e64d986.png)
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3 . (教材呈现)如图是华师版九年级上册数学教材第77页的部分内容.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/24/3a62f7e0-7863-4d81-89cf-ad81b7ab9d32.png?resizew=457)
(定理证明)(1)请根据教材内容,结合图①,写出证明过程.
(定理应用)(2)如图②,四边形
中,
分别为
的中点,边
延长线交于点
,
,则
的度数是_______.
(3)如图③,矩形
中,
,
,点
在边
上,且
.将线段
绕点
旋转一定的角度
,得到线段
,
是线段
的中点,直接写出旋转过程中线段
长的最大值和最小值.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/24/3a62f7e0-7863-4d81-89cf-ad81b7ab9d32.png?resizew=457)
(定理证明)(1)请根据教材内容,结合图①,写出证明过程.
(定理应用)(2)如图②,四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c60c6db49930fbbab66b1fab54f5449e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66d13b8ae3d0d5e75afc0e862d5c2dd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32bc8658ac6da92cfaf719cce9259c51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e6414089941feb5d8a4a6a49566b9ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45a8a837c11c07073da3ff751d70278.png)
(3)如图③,矩形
![](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/d0d5a2cd05e4476fc72271e8fdb59a9a.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/5d2e57629856cc8ed7ab28ca9ca76d5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c54ce139ae5d63691cac8a1ce5bbfe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/24/fe0915cc-bdd2-4027-82b9-3168c9a35cfe.png?resizew=392)
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2023-04-17更新
|
276次组卷
|
6卷引用:河南省南阳市宛城区2020-2021学年九年级上学期期中数学试题
河南省南阳市宛城区2020-2021学年九年级上学期期中数学试题(已下线)专题18.1 平行四边形-【帮课堂】2022-2023学年八年级数学下册同步精品讲义(人教版)(已下线)第9章 中心对称图形-平行四边形 章末检测卷-2022-2023学年八年级数学下册重难题型全归纳及技巧提升专项精练(苏科版)(已下线)专题6.3 三角形的中位线-【帮课堂】2022-2023学年八年级数学下册同步精品讲义(北师大版)(已下线)第六章 平行四边形 章末检测卷-2022-2023学年八年级数学下册重难题型全归纳及技巧提升专项精练(北师大版)(已下线)第4章 平行四边形 章末检测卷-2022-2023学年八年级数学下册重难题型全归纳及技巧提升专项精练(浙教版)
4 . 如图1,点O是矩形ABCD的中心,
,
,动点P从点A出发,以每秒
个单位长度的速度沿折线
向终点
运动,连接PO,以PO,PB为边作平行四边形OPBE,设点
的运动时间为
秒.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/26/1eb7f17f-5035-4ada-b3e7-31c4b36b915e.png?resizew=439)
(1)当点
落在边
上时,平行四边形OPBE的周长为______;
(2)当点
在边
上运动时,若四边形OPBE是轴对称图形,则
的值为______;
(3)在点
的运动过程中,
长度的最大值为
,最小值
,则
的值是______;
(4)如图
,当点
在边
上运动时,以
为对角线作正方形OFPG(O、F、P、G逆时针排序
,则点
的运动路径长为______.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07140f277a35733d8c97577ccdd4e3ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/722b4403b1cd40188f0bfd1098ec9095.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/26/1eb7f17f-5035-4ada-b3e7-31c4b36b915e.png?resizew=439)
(1)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(3)在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9f2416d1f75a45a314331146550832e.png)
(4)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.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/ef49a3ca580a144cc65a609c167facc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
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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.
您最近一年使用:0次
2022-07-04更新
|
397次组卷
|
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)
6 . 在▱ABCD中,∠ABC=60°,AB=4,BC=6.点E'在BC边上且
=4,将B
绕点B逆时针旋转a°得到BE(0°<a<180°).
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/30/b2f28918-2d71-44d1-8068-c53e8652d719.png?resizew=514)
(1)如图1,当∠EBA=90°时,求S△BCE;
(2)如图2,在旋转过程中,连接CE,取CE中点F,作射线BF交直线AD于点G.
①求线段BF的取值范围;
②当∠EBF=120°时,求证:BC﹣DG=2BF;
(3)如图3.当∠EBA=90°时,点S为线段BE上一动点,过点E作EM⊥射线AS于点M,N为AM中点,直接写出BN的最大值与最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926d2094777538ba6a70ea65d5061ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3b1a5427d8ff23df0f3ec194756c84c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/30/b2f28918-2d71-44d1-8068-c53e8652d719.png?resizew=514)
(1)如图1,当∠EBA=90°时,求S△BCE;
(2)如图2,在旋转过程中,连接CE,取CE中点F,作射线BF交直线AD于点G.
①求线段BF的取值范围;
②当∠EBF=120°时,求证:BC﹣DG=2BF;
(3)如图3.当∠EBA=90°时,点S为线段BE上一动点,过点E作EM⊥射线AS于点M,N为AM中点,直接写出BN的最大值与最小值.
您最近一年使用:0次
7 . 如图1,把一个含45°角的直角三角板ECF和一个正方形ABCD摆放在一起,使三角板的直角顶点和正方形的顶点C重合,点E、F分别在正方形的边CB、CD上,连AF
取AF的中点M,EF的中点N,连接MD、MN.
![](https://img.xkw.com/dksih/QBM/2021/12/27/2881475738517504/2945357659684864/STEM/49d7e70d-f2f1-49b0-9468-8b4cfcd9a553.png?resizew=327)
(1)请判断MD与MN之间的数量关系,直接写出结论;
(2)将图1中的直角三角板ECF绕点C顺时针旋转180°得到图2,其他条件不变,则(1)中的结论还成立吗?若成立,请加以证明;若不成立,请说明理由.
(3)连接DN,若AB=3,CE=2,将图1中的直角三角板ECF绕点C在平面内自由旋转,其他条件不变,请直接写出△DMN面积的最大值和最小值.
![](https://img.xkw.com/dksih/QBM/2021/12/27/2881475738517504/2945357659684864/STEM/66c22e876f6446cc861445be1fb5be8e.png?resizew=3)
![](https://img.xkw.com/dksih/QBM/2021/12/27/2881475738517504/2945357659684864/STEM/49d7e70d-f2f1-49b0-9468-8b4cfcd9a553.png?resizew=327)
(1)请判断MD与MN之间的数量关系,直接写出结论;
(2)将图1中的直角三角板ECF绕点C顺时针旋转180°得到图2,其他条件不变,则(1)中的结论还成立吗?若成立,请加以证明;若不成立,请说明理由.
(3)连接DN,若AB=3,CE=2,将图1中的直角三角板ECF绕点C在平面内自由旋转,其他条件不变,请直接写出△DMN面积的最大值和最小值.
您最近一年使用:0次
2022-03-27更新
|
328次组卷
|
2卷引用:2022年辽宁省抚顺市东洲区九年级模拟检测(一)数学试题
8 . 如图,
和
中,
,
,
,连接
,点M,N,P分别是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/12/e0b8d3c7-24dc-43fe-8888-6836aff91fa3.png?resizew=264)
(1)请你判断
的形状,并证明你的结论.
(2)将
绕点A旋转,若
,请直接写出
周长的最大值与最小值.
![](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/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d212c1709b8e72a055cf1b5381ef64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26813466e2ee49a493881a4384fc8748.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9153faa6601e0858b1876256eb5b583.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/12/e0b8d3c7-24dc-43fe-8888-6836aff91fa3.png?resizew=264)
(1)请你判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ed4c4e8edbd179f3fc38a6653f18c1.png)
(2)将
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b20ef58c7d76b981cc93ee42d80c582c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d23b488f961d9fde37feb7f5c497c0d9.png)
您最近一年使用:0次
2022-01-23更新
|
222次组卷
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3卷引用:重庆市渝中区2021-2022学年九年级上学期期末数学试题
9 . 如图①,在
中,
,
,点
、
分别在边
、
上,
,连接
,点
、
、
分别为
、
、
的中点.
(1)观察猜想:图①中,线段
与
的数量关系是_____________,用含
的代数式表示
的度数是________________________;
(2)探究证明:把
绕点
顺时针方向旋转到图②的位置,连接
,
,
,当
时,判断
的形状,并说明理由;
(3)拓展延伸:把
绕点
在平面内任意旋转,若
,
,
,请直接写出线段
的最大值和最小值.
![](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/cb2cf0e95fdf1fd8a5b01d3dfd905e08.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/e2d212c1709b8e72a055cf1b5381ef64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(1)观察猜想:图①中,线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8ffe24cf9f327aeb241225ab15ab1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45a8a837c11c07073da3ff751d70278.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/411461db15ee8086332c531e086c40c7.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/2d03f73bec20b60bc7608972607f5a9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ed4c4e8edbd179f3fc38a6653f18c1.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/33ac762a2899a58faa0d3ab44f1281fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16e0c5cb53fd85b7a23f0580df6bb49a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://img.xkw.com/dksih/QBM/2020/10/9/2567253982699520/2567861177229312/STEM/4f17f001-23f8-48ef-88e5-d7223141c95c.png?resizew=664)
您最近一年使用:0次
10 . 已知
和
都是等腰三角形,
,
,
,且
,连接
,且
,直线
交直线
于点F.
与
的位置关系,并说明理由;
(2)如图2,依次取
、
的中点M、N,连接
、
,求证:
;
(3)如图3,在(2)的条件下,连接
,若
,在将
绕点A旋转的过程中,请直接写出线段
的最大值.
![](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/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d212c1709b8e72a055cf1b5381ef64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/316908a938af254508f414226ba328cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28c65319e9026d1db4d468f69fd8f9ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cc9c9a1c828f5b3c718e2a98a749192.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
(2)如图2,依次取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2273ae1ee99cec9c1304323bc9ebf75f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2d028eaea6f3485e34f521865f27d71.png)
(3)如图3,在(2)的条件下,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1460aa3d83df61f6c411b34412135451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80651f797ab9dccfd7163c605b091ad5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1460aa3d83df61f6c411b34412135451.png)
您最近一年使用:0次