Question

The circumference of two circles are in ratio 2 is to 3 .Find the ratio of their areas

Answer 1

(r1/r2)= 2/3
(r1/r2)^2 = 4/9

(pi*r1^2/pi*r2^2) = (4/9)

A=pi*r^2

(A1/A2)=(4/9)

Answer 2

ratio of circumference=2:3

ratio of radius=circumference/circumference=2πr/2πr

2/3=2πr/2πr

r/r=2/3=2:3

ratio of area=πr square/πr square

=4/9

=4:9