满分5 >
初中数学试题 >
在直角梯形ABCD中,AD∥BC,∠C=90°,∠A=2∠B,则∠B= .
在直角梯形ABCD中,AD∥BC,∠C=90°,∠A=2∠B,则∠B= .
考点分析:
相关试题推荐
已知圆锥的底面半径为5cm,侧面积为65πcm
2,设圆锥的母线与高的夹角为θ,如图所示,则sinθ的值为( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185840494797833/SYS201311011858404947978009_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185840494797833/SYS201311011858404947978009_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185840494797833/SYS201311011858404947978009_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185840494797833/SYS201311011858404947978009_ST/2.png)
D.
查看答案
在一幅长80cm,宽50cm的矩形风景画的四周镶一条金色纸边,制成一幅矩形挂图,如图所示,如果要使整个挂图的面积是5400cm
2,设金色纸边的宽为xcm,那么x满足的方程是( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185840494797833/SYS201311011858404947978008_ST/images0.png)
A.x
2+130x-1400=0
B.x
2+65x-350=0
C.x
2-130x-1400=0
D.x
2-65x-350=0
查看答案
如图,以O为圆心的两个同心圆中,大圆的弦AB切小圆于点C,若∠AOB=120°,则大圆半径R与小圆半径r之间满足( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185840494797833/SYS201311011858404947978007_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185840494797833/SYS201311011858404947978007_ST/0.png)
B.R=3r
C.R=2r
D.
查看答案