The ratio between area of two circles is 81 : 64. What will be the ratio of their radius?
Answer & explanation
Correct answer: option 4
Ratio of Area = \(\pi \) (r1)2 : \(\pi \)(r2)2 = (r1)2 : (r2)2
⇒ (r1)2 : (r2)2 = 81 : 64
⇒ r1: r2= 9 : 8
Ratio of radius = 9 : 8