Question

The ratio between the area of two circles is 4:9 . Find the ratio between their radii

Answer 1

$area = \pi {r}^{2}$
a1/a2=r1/r2
4/9=[r1/r2]^2
r1/r2=2/3

Answer 2

let 1 radius = r
let other radius=R

πr^2=4
πR^2=9

r^2=√4
R^2=√9

r=2
R=3

therefore, ratio of radio=2:3