Question

Circumference of two circles are in the ratio 4:9.Then what will be the ratio of their areas?

Answer 1

Let the radius of two circles be r and R

2πr/ 2πR =4:9

r/R = 4:9

area of the circle = π× radius×radius

area of circle1/ area of circle 2=

πr^2/πR^2

=r^2/R^2

{4}^{2} \div {9}^{2}

=16/81