The ratio of the radius of two circles is 1: 4, and then the ratio of their areas is?
Choose one
A) 1: 16 B) 1: 6 C) 1: 9 D) 1: 3 E) 1: 2
r1: r2 = 1: 4   Πr12: Πr22   r12: r22 = 1: 16   1: 16nswer:1: 16
<result>A</result>
The ratio of the radius of two circles is 1: 4, and then the ratio of their areas is?