The ratio between area of two circles is 9 : 25.  What will be the ratio of their radius?

9 : 25 3 : 5 81 : 625  9 : 5

3 : 5

Ratio of Area = \(\pi \) (r1)2 : \(\pi \)(r2)2 = (r1)2 : (r2)2 ⇒ (r1)2 : (r2)2 = 9 : 25 ⇒ r1: r2= 3 : 5 Ratio of radius = 3 : 5