满分5 >
初中数学试题 >
已知:如图,AB是⊙O的弦,半径OC⊥AB于点D,且AB=8cm,OC=5cm,...
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103102335646078177/SYS201311031023356460781010_ST/images0.png)
已知:如图,AB是⊙O的弦,半径OC⊥AB于点D,且AB=8cm,OC=5cm,则DC的长为( )
A.3cm
B.2.5cm
C.2cm
D.1cm
考点分析:
相关试题推荐
如图所示,在圆⊙O内有折线OABC,其中OA=8,AB=12,∠A=∠B=60°,则BC的长为( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103102335646078177/SYS201311031023356460781009_ST/images0.png)
A.19
B.16
C.18
D.20
查看答案
如图,在半径为5的⊙O中,若弦AB=8,则△AOB的面积为( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103102335646078177/SYS201311031023356460781008_ST/images0.png)
A.24
B.16
C.12
D.8
查看答案
圆的半径为13cm,两弦:AB∥CD,AB=24cm,CD=10cm,则两弦AB、CD的距离是( )
A.7cm
B.17cm
C.12cm
D.7cm或17cm
查看答案
如图,△ABC内接于⊙O,D为线段AB的中点,延长OD交⊙O于点E,连接AE,BE,则下列五个结论①AB⊥DE,②AE=BE,③OD=DE,④∠AEO=∠C,⑤弧AE=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103102335646078177/SYS201311031023356460781006_ST/0.png)
弧AEB,正确结论的个数是( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103102335646078177/SYS201311031023356460781006_ST/images1.png)
A.2
B.3
C.4
D.5
查看答案
下列说法正确的是( )
A.矩形的对角线互相垂直
B.平分弦的直径垂直于弦
C.正方形的对角线互相垂直平分且相等
D.菱形的对角线相等
查看答案