如图:A、B、C在⊙O上,∠C=20°,∠B=50°,则∠A=( )
![](https://img.xkw.com/dksih/QBM/2020/3/16/2420941688365056/2421577791963137/STEM/7819677eb45d47a0b71b8507fba12cef.png?resizew=92)
![](https://img.xkw.com/dksih/QBM/2020/3/16/2420941688365056/2421577791963137/STEM/7819677eb45d47a0b71b8507fba12cef.png?resizew=92)
A.20° | B.25° | C.30° | D.40° |
更新时间:2020-03-18 12:09:00
|
相似题推荐
单选题
|
适中
(0.65)
【推荐1】下列是直角三角形的有( )个
①
中
;②
的三内角之比为
:
:
;③
的三边平方之比为
:
:
;④ 三角形三边之比为
:
:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea8a2749c4c2150fbdd4549f59efc8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b06e95b57b7a81cd81d05557a11fa92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
单选题
|
适中
(0.65)
【推荐2】下面说法正确的个数有( )
①由三条线段首尾顺次连接所组成的图形叫做三角形;②全等三角形的周长和面积相等;
③若
,则
为直角三角形;④如果
,那么
.
①由三条线段首尾顺次连接所组成的图形叫做三角形;②全等三角形的周长和面积相等;
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1ac3781e2ca56262e180134d9200bed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432d77fe5ad3032d59a237dd94c8a638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ba64a16536303b5d2186f6a5b6567e1.png)
A.0个 | B.1个 | C.2个 | D.3个 |
您最近一年使用:0次
单选题
|
适中
(0.65)
真题
【推荐1】如图,AB是⊙O的直径,AB=8,点M在⊙O上,
,N是弧MB的中点,P是直径AB上的一动点,若MN=1,则
周长的最小值为( )
![](https://img.xkw.com/dksih/QBM/2015/7/14/1573871296077824/1573871302180864/STEM/2331c813-5160-4b24-b014-cc0939f9e44a.png?resizew=196)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8469fd74a73c8829560b56591c553172.png)
![](https://img.xkw.com/dksih/QBM/2015/7/14/1573871296077824/1573871302180864/STEM/f0fdbd0fc6a84930b5928e54b1e36903.png)
![](https://img.xkw.com/dksih/QBM/2015/7/14/1573871296077824/1573871302180864/STEM/2331c813-5160-4b24-b014-cc0939f9e44a.png?resizew=196)
A.4 | B.5 | C.6 | D.7 |
您最近一年使用:0次
单选题
|
适中
(0.65)
【推荐2】下列说法错误的是( )
A.直径是圆中最长的弦 |
B.圆内接平行四边形是矩形 |
C.90°的圆周角所对的弦是直径 |
D.相等的圆周角所对的弧相等 |
您最近一年使用:0次
单选题
|
适中
(0.65)
【推荐1】如图,四边形ABCD内接于⊙O,BC是直径,AD=DC,∠ADB=20º,则∠ACB,∠DBC分别为( )
![](https://img.xkw.com/dksih/QBM/2017/12/21/1843134855495680/1844015976890368/STEM/a956106a-99e3-4e3c-acab-0fc4723c8ba7.png?resizew=146)
![](https://img.xkw.com/dksih/QBM/2017/12/21/1843134855495680/1844015976890368/STEM/a956106a-99e3-4e3c-acab-0fc4723c8ba7.png?resizew=146)
A.15º与30º | B.20º与35º | C.20º与40º | D.30º与35º |
您最近一年使用:0次
单选题
|
适中
(0.65)
名校
【推荐2】如图,点A、B、C、D在
上,
,
,
,则
( )
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/23/ef533105-1734-4533-b43c-4246e17f5b85.png?resizew=133)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b608b17ab6f5fbcb40a7847090e42e4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d65639672f444b3d4dc6fc4f357ddbd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c42e0153bc0cc5b537e8b733740c069.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acb663fe83b1f7e93e13d91cc6460f9c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/23/ef533105-1734-4533-b43c-4246e17f5b85.png?resizew=133)
A.30° | B.50° | C.70° | D.80° |
您最近一年使用:0次