1 . 如图,矩形ABCD是⊙O的内接矩形,⊙O半径为5,AB=8,点E、F分别是弦CD、BC上的动点,连结EF,∠EAF始终保持等于45°.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/26/d2ed1736-767f-4b64-8e7b-c097f44e1934.png?resizew=230)
(1)求AD的长度.
(2)已知DE=
,求BF的长度.
(3)试探究△AEF的面积是否存在最小值,若存在,请求出它的最小值;若不存在,请说明理由.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/26/d2ed1736-767f-4b64-8e7b-c097f44e1934.png?resizew=230)
(1)求AD的长度.
(2)已知DE=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a85a2c984df17f7ef91d014d931410d.png)
(3)试探究△AEF的面积是否存在最小值,若存在,请求出它的最小值;若不存在,请说明理由.
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2 . 如图,在正方形
中,
是边
上的动点(与点
、
不重合),且
,
于点
,
与
的延长线交于点
,连接
、
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/17/6e5326d4-64da-46eb-aae0-2170a7f8270b.png?resizew=188)
(1)求证:①![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad09a769a75b107390b9eeccc929f761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f9c59463fdce9259f60b935164dd00e.png)
;②
;
(2)若
,在点
运动过程中,探究:
①线段
的长度是否改变?若不变,求出这个定值;若改变,请说明理由;
②当
为何值时,
为等腰直角三角形.
![](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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6618b4d41917e695da2356c016242ba4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51246bfbcf524ed6da2eceec37712470.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0e57a13c665af88f326c9890072bf73.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/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/17/6e5326d4-64da-46eb-aae0-2170a7f8270b.png?resizew=188)
(1)求证:①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad09a769a75b107390b9eeccc929f761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f9c59463fdce9259f60b935164dd00e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6830ebecddbd9759be626289c408e4f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f744502271fb81059db970e5840575be.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
①线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81cda90244126e0e213e6f3f1930026d.png)
您最近一年使用:0次
2020-06-27更新
|
410次组卷
|
2卷引用:2020年海南省海口市九年级学业模拟考试数学试题
解题方法
3 . 如图1,
中,
,直线
点
是
上的动点,过
三点的圆交直线
于点
,连结
.
![](https://img.xkw.com/dksih/QBM/2020/6/18/2486883556614144/2492414472257536/STEM/9cc1a4dafebd4ae4ad045b93256cbc8f.png?resizew=204)
当点
与点
重合时如图2所示,连
,求证:四边形
是矩形.
![](https://img.xkw.com/dksih/QBM/2020/6/18/2486883556614144/2492414472257536/STEM/11ff3bb9680a46bfb126338e93323331.png?resizew=192)
如图3,当
与过
三点的圆相切时,求
的长.
![](https://img.xkw.com/dksih/QBM/2020/6/18/2486883556614144/2492414472257536/STEM/e86c675fca954f35aaa54c87a09af4c8.png?resizew=203)
作点
关于直线
的对称点
,试判断
能否落在直线
上,若能请直接写出
的长,若不能说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfa8cee7d2463f6f7d352e8b65f47cf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11de92ecd6ebb483c74dee0f6335e34a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9899680baf785e2f705d4cd4f589340.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7a922719e276f2cecbc2967ff54f182.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://img.xkw.com/dksih/QBM/2020/6/18/2486883556614144/2492414472257536/STEM/9cc1a4dafebd4ae4ad045b93256cbc8f.png?resizew=204)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bf6c84731e5e1bd335ecfc2d36c3d81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9df19df3b0eb0eedd2b9eaa440996fd8.png)
![](https://img.xkw.com/dksih/QBM/2020/6/18/2486883556614144/2492414472257536/STEM/11ff3bb9680a46bfb126338e93323331.png?resizew=192)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f53190d6ead827a6338b9de847aeaf1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7a922719e276f2cecbc2967ff54f182.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/2020/6/18/2486883556614144/2492414472257536/STEM/e86c675fca954f35aaa54c87a09af4c8.png?resizew=203)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f62295c36d2e2174908c2bec0eb5b30f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2d7ffb7889a31b267a85f1ea238138e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2d7ffb7889a31b267a85f1ea238138e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
您最近一年使用:0次
4 . 如图,在
中,
,以
为直径的
交
于点
,
是
上的一点,且
,
的延长线交
于点
,连接
,
.
(1)求证:
是
的中点;
(2)求证:
;
(3)若
,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f8f88798ec42a58dccd212586382b23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.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/83bb3820bab977db734f4335e4fde720.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7649728e8210b186a7bddc85da7c8885.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.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/e6e490f703eb6c9bb1278c78ebc2d661.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7296bb43cd22094550df7dc2de4d9afb.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a7a6901af6bf907d2baf1b42a0a704d.png)
![](https://img.xkw.com/dksih/QBM/2020/5/21/2467730157920256/2468321655119872/STEM/5331463340a94ab394cb7032ed24fb6d.png?resizew=256)
您最近一年使用:0次