在Rt△ABC中，∠ACB=90°，AC=12，BC=9，D是AB的中点，G是△ABC的重心，如果以点D为圆心DG为半径的圆和以点C为圆心半径为 r 的圆相交，那么 r 的取值范围是_刷题宝

题干

在Rt△ABC中，∠ACB=90°，AC=12，BC=9，D是AB的中点，G是△ABC的重心，如果以点D为圆心DG为半径的圆和以点C为圆心半径为 r 的圆相交，那么 r 的取值范围是（）

A： $r < 5$ ；

B： $r > 5$ ；

C： $r < 10$ ；

D： $5 < r < 10$ ．

上一题下一题 0.0难度选择题更新时间:2018-02-07 02:01:05

答案(点此获取答案解析）

D

同类题1

补全对话。

A：Hey, Dale! You look tired．____

B：Yes，I did．Last night I watched a movie on TV

A：How was it?

B：It was great．What did you do last night?

A：____．

B：Oh，Eric?____

A：Yes，he did．

B：____

A：Yesterday morning．

B：____

A：He said it was very good. He visited many interesting places．

B：Mm London is an interesting city．If I have time，I'll go to visit it．

A．I went to visit Eric．

B．How long did he stay there?

C．When did he come back?

D．Did you go to bed late last night?

E．How was the weather there?

F．Did Eric come back from London?

G．How was his vacation?

同类题2

下列有关无机盐的叙述中，错误的是（）

同类题3

如图所示是一只磁控猴子，只要你拿走它手上的香蕉，它就不停地大吵大闹；你把香蕉还给它，它就停止吵闹．香蕉的作用相当于电路中的（）

同类题4

　　　is known to us all is that the old scientist, for　　life was hard in the past, still works very hard in his eighties．

同类题5

i是虚数单位，复数 $\frac{1 - 3 i}{1 - i}$ 为( )

小学学科试题库

初中学科试题库

高中学科试题库