The ratio of the radius of two circles is 2: 5, and then the ratio of their areas is?
Pick
A) 4:25
B) 2:9
C) 1:9
D) 3:7
E) 3:4
r1: r2 = 2: 5   Î r1^2: Î r2^2   r1^2: r2^2 = 4:25   4:25nswer: 4:25
<result>A</result>
The ratio of the radius of two circles is 2: 5, and then the ratio of their areas is?