满分5 >
初中数学试题 >
(2002•宁夏)已知圆内接正六边形的周长为18,那么圆的面积为( ) A.18...
(2002•宁夏)已知圆内接正六边形的周长为18,那么圆的面积为( )
A.18π
B.9π
C.6π
D.3π
考点分析:
相关试题推荐
(2002•泉州)先作半径为
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886025_ST/0.png)
的圆的内接正方形,接着作上述内接正方形的内切圆,再作上述内切圆的内接正方形,…,则按以上规律作出的第7个圆的内接正方形的边长为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886025_ST/1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886025_ST/2.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886025_ST/3.png)
D.
查看答案
(2002•山西)如图,BC是⊙A的内接正十边形的一边,BD平分∠ABC交AC于点D,则下列结论不成立的是( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886024_ST/images0.png)
A.BC=BD=AD
B.BC
2=DC•AC
C.△ABC的三边之长为1:1:
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886024_ST/0.png)
D.BC=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886024_ST/1.png)
AC
查看答案
(2002•上海)下列命题中,正确的是( )
A.正多边形都是轴对称图形
B.正多边形一个内角的大小与边数成正比例
C.正多边形一个外角的大小随边数的增加而增大
D.边数>3的正多边形的对角线长都相等
查看答案
(2002•绍兴)边长为a的正六边形的边心距为( )
A.a
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886022_ST/0.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886022_ST/1.png)
D.2a
查看答案
(2002•太原)圆的内接正四边形的边长与半径的比为( )
A.2:1
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886021_ST/0.png)
:l
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232550768788637/SYS201310212325507687886021_ST/1.png)
:l
D.3:1
查看答案