如图,AB是⊙O的直径,C,G是⊙O上两点,且
,过点C的直线CD⊥BG于点D,交BA的延长线于点E,连接BC,交OD于点F.
(1)求证:CD是⊙O的切线;
(2)若
,求证:AE=AO;
(3)连接 AD,在(2)的条件下,若CD
,求AD的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/684a4729e41181077d6d9ef41d68e005.png)
(1)求证:CD是⊙O的切线;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c769a7c7e4aa5bcc9425daeb45eabc8.png)
(3)连接 AD,在(2)的条件下,若CD
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://img.xkw.com/dksih/QBM/2020/3/31/2431350232006656/2432241942102016/STEM/df6f05b39591420ba548926b0360d124.png?resizew=190)
更新时间:2020-04-01 19:11:48
|
相似题推荐
解答题-证明题
|
较难
(0.4)
【推荐1】如图1,已知四边形ABCD是矩形,点E在AD上,AE=AB,EC与BD相交于点F,且BD⊥EC
![](https://img.xkw.com/dksih/QBM/2022/3/15/2936963317055488/2938839302823936/STEM/7cba1acc6f1048d58c6bc6fe3c2d22c8.png?resizew=222)
(1)连接BE,求证:△AFD∽△BED;
(2)如图2,连接AF并延长交CD于点G,求∠DFG的度数;
(3)若AD=1,求AB的长
![](https://img.xkw.com/dksih/QBM/2022/3/15/2936963317055488/2938839302823936/STEM/7cba1acc6f1048d58c6bc6fe3c2d22c8.png?resizew=222)
(1)连接BE,求证:△AFD∽△BED;
(2)如图2,连接AF并延长交CD于点G,求∠DFG的度数;
(3)若AD=1,求AB的长
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】如图,在菱形ABCD中,∠ABC=60°,经过点A的直线(不与BD垂直)与对角线BD所在直线交于点E,过点B,D分别作直线BD的垂线交直线AE于点F,H.
(1)当点E在如图①位置时,求证:BF﹣DH=
BD;(提示:延长DA交BF于G)
(2)当点E在图②、图③的位置时,直接写出线段BF,DH,BD之间的数量关系,不需要证明;
(3)在(1)、(2)的条件下,若DH=1,BD=4
,则tan∠DHE= .
(1)当点E在如图①位置时,求证:BF﹣DH=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
(2)当点E在图②、图③的位置时,直接写出线段BF,DH,BD之间的数量关系,不需要证明;
(3)在(1)、(2)的条件下,若DH=1,BD=4
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/13/e0eedee7-a521-4cf1-814c-2f146ccdedda.png?resizew=572)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐1】如图,已知⊙O的半径长为1,AB、AC是⊙O的两条弦,且AB=AC,BO的延长线交AC于点D,连接OA、OC.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/16/fb262688-b84a-42f3-a0c6-9d75ae61b980.png?resizew=357)
(1)求证:△OAD∽△ABD;
(2)当△OCD是直角三角形时,求B、C两点的距离;
(3)记△AOB、△AOD、△COD的面积分别为S1、S2、S3,如果S22=S1•S3,试证明点D为线段AC的黄金分割点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/16/fb262688-b84a-42f3-a0c6-9d75ae61b980.png?resizew=357)
(1)求证:△OAD∽△ABD;
(2)当△OCD是直角三角形时,求B、C两点的距离;
(3)记△AOB、△AOD、△COD的面积分别为S1、S2、S3,如果S22=S1•S3,试证明点D为线段AC的黄金分割点.
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
真题
名校
【推荐2】如图,
是
的切线,切点为
,
是
的直径,连接
交
于
.过
点作
于点
,交
于
,连接
,
.
![](https://img.xkw.com/dksih/QBM/2019/10/29/2322445476134912/2322597282291712/STEM/27620d5d34374c8e9a515f731a898746.png?resizew=208)
(1)求证:
是
的切线;
(2)求证:
为
的内心;
(3)若
,
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.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/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e74d4d587b12f0c7714838330b2b84ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/2019/10/29/2322445476134912/2322597282291712/STEM/27620d5d34374c8e9a515f731a898746.png?resizew=208)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53502463cc76201000e02df314e58769.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a362daefde38d28a6b973c872c703866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef49a3ca580a144cc65a609c167facc1.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐3】某数学活动小组在一次活动中,对一个数学问题作如下探究:
【问题探究】如图1,
,
为
的两条弦(
),点C为
的中点,过C作
、垂足为E.求证:
.
小明同学的思路是:如图2.在BE上截取
,连接
,
,
,
…请你按照小明的思路完成上述问题的证明过程.
【结论运用】如图3,
是
的内接等边三角形,点D是
上一点,
,连接
,
.过点A作
,垂足为E.若
,求
的周长.
【变式探究】如图4,若将(问题探究)中“点C为
的中点”改为“点C为优弧
的中点”,其他条件不变,请写出
、
、
之间的等量关系,并加以证明.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/ebf87d87-cfe4-46f1-91e3-8a844fa82f85.png?resizew=203)
【问题探究】如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ca4ac471d3fb5f7156c69a249f4f225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a45b04cc3e5adaeff6f9e01e29032803.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e25da3d724f859ac0c1c3d846ac49d.png)
小明同学的思路是:如图2.在BE上截取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c280fc03fdbcf37491a8573850a1df95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
【结论运用】如图3,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2bdcd23d2c26d9df0b4756d8a715673.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4611ceb2a28f7a7e4d24266d7f99b22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c406e7d1e7977dd5b30ef81cfdc8e8d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661ff55b5ebbadfb600989af3cfce2fd.png)
【变式探究】如图4,若将(问题探究)中“点C为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9cf468f5132e14ee1d8cc766808b11af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/ebf87d87-cfe4-46f1-91e3-8a844fa82f85.png?resizew=203)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/5a412ab1-ca71-48fa-9d1b-1ec06d502aa3.png?resizew=203)
您最近一年使用:0次