1 . 如图,在
中,
,
分别为
的中点,
交
的延长线于点
.
![](https://img.xkw.com/dksih/QBM/2016/10/26/1573097030287360/1573097036259328/STEM/e1dd938805534722994c7209e3a0e31b.png)
(1)求证:四边形
是平行四边形;
(2)当
时,求证:四边形
是菱形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd936a2405709574af0a73543d94ad9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/934f9b1b3bf5b1a3ef81c03aaca1700e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb2d55057f050ff719ac49596532f50c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c60b356c3dec22c6c5d6af51d93c127e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b56bfe91a487cd635b9e075a31385322.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://img.xkw.com/dksih/QBM/2016/10/26/1573097030287360/1573097036259328/STEM/e1dd938805534722994c7209e3a0e31b.png)
(1)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a94aca49ac8b16079fc50192912a3f39.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab49764544bfc02ae2edb7b701b3c348.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a94aca49ac8b16079fc50192912a3f39.png)
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名校
2 . 已知,如图,
是圆
的直径,点
为圆
上一点,
于点
,交圆
于点
,
与
交于点
,点
为
的延长线上一点,且
.
![](https://img.xkw.com/dksih/QBM/2016/9/7/1573000916713472/1573000922562560/STEM/8a9afd1397b845d5b8d70b1c1016d2db.png)
(1)求证:
是圆
的切线;
(2)求证:
;
(3)若圆
的半径为5,
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1074256fbf5ca9592f8be962fb401d4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.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/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9909a7084fde8170536cdece59e987ad.png)
![](https://img.xkw.com/dksih/QBM/2016/9/7/1573000916713472/1573000922562560/STEM/8a9afd1397b845d5b8d70b1c1016d2db.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d67471791dc53ef3f0dc4431643868bb.png)
(3)若圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15ee608882881caff2f1e223177424ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcdae78f4d3b8d8213ac3ac9a9567eb5.png)
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3 . 如图,
和
是有公共顶点的等腰直角三角形,
,点
为射线
与射线
的交点.
![](https://img.xkw.com/dksih/QBM/2016/10/26/1573097030287360/1573097036488704/STEM/25d1a4a06abc49828859ed230bf94878.png)
(1)求证:
;
(2)若
,把
绕点
旋转,
①当
时,求
的长;
②直接写出旋转过程中线段
长的最小值与最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd936a2405709574af0a73543d94ad9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a7d5cf4f2bf91fe0f7a99f2ba358c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b0a9fdb7195907b514f3aad70a855e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://img.xkw.com/dksih/QBM/2016/10/26/1573097030287360/1573097036488704/STEM/25d1a4a06abc49828859ed230bf94878.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/421291381be28da4bd16560fd383b4a9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05a13ebb6050fbd7f4491451ca871469.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a7d5cf4f2bf91fe0f7a99f2ba358c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56ac7c8fa5cb10b27f2f41976780a334.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
②直接写出旋转过程中线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
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4 . 如图,在⊙O中,点P为直径BA延长线上一点,直线PD切⊙O于点D,过点B作BH⊥PD,垂足为H,BH交⊙O于点C,连接BD.
![](https://img.xkw.com/dksih/QBM/2016/10/6/1578976699621376/1578976700203008/STEM/229f242f82aa4ddbba354fa389283b31.png)
(1)求证:BD平分∠ABH;
(2)如果AB=10,BC=6,求BD的长;
(3)在(2)的条件下,当E是弧AB的中点,DE交AB于点F,求DE·DF的值.
![](https://img.xkw.com/dksih/QBM/2016/10/6/1578976699621376/1578976700203008/STEM/229f242f82aa4ddbba354fa389283b31.png)
(1)求证:BD平分∠ABH;
(2)如果AB=10,BC=6,求BD的长;
(3)在(2)的条件下,当E是弧AB的中点,DE交AB于点F,求DE·DF的值.
您最近一年使用:0次
5 . 已知圆
的方程为:
,直线的方程为
,点
在直线上,过点
作圆
的切线
,切点为
.
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/33bca3e29e0c4b7f9d5131abd5ea9285.png)
(1)若
,求点
的坐标;
(2)若点
的坐标为
,过点
的直线与圆
交于
两点,当
时,求直线
的方程;
(3)求证:经过
(其中点
为圆
的圆心)三点的圆必经过定点,并求出所有定点的坐标.
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/3d5032b8e16a48278074a9b13b8ea604.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/6abf4320c25a4066a7e2a24e538245ee.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/9d100565713a4563a2fd17c899a1607e.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/4c31d272157744d7be133a5531fb8d1f.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/4c31d272157744d7be133a5531fb8d1f.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/3d5032b8e16a48278074a9b13b8ea604.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/baabd968640d4c81a564d36fdafe7bb7.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/52b6d604ae434a779657ffd90d2bde4f.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/33bca3e29e0c4b7f9d5131abd5ea9285.png)
(1)若
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/a04519a6852340caa2812a0efeb7725e.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/4c31d272157744d7be133a5531fb8d1f.png)
(2)若点
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/4c31d272157744d7be133a5531fb8d1f.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/0845fad52439481babaf3375ad63f674.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/4c31d272157744d7be133a5531fb8d1f.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/3d5032b8e16a48278074a9b13b8ea604.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/984da381678a48959f776f3216d78b9f.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/69d161424141467b8315d21609279a9e.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/279b4101d173432fbb45f681faed7d73.png)
(3)求证:经过
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/be2e2157747d4fe5b7d90b4757732f45.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/3d5032b8e16a48278074a9b13b8ea604.png)
![](https://img.xkw.com/dksih/QBM/2014/3/28/1571585931689984/1571585937055744/STEM/3d5032b8e16a48278074a9b13b8ea604.png)
您最近一年使用:0次