The ratio of the radius of two circles is 3: 4, and then the ratio of their areas is? Pick
A) 1:7  B) 9:16  C) 1:9  D) 3:7  E) 3:4
r1: r2 = 3:4   Î r1^2: Î r2^2   r1^2: r2^2 = 9:16   Answer: 9:16
<result>B</result>
The ratio of the radius of two circles is 3: 4, and then the ratio of their areas is?