Question

The diameters of two circles are 4 cm and 6 cm respectively .find the ratio of their areas

Answer 1

A¹ = πr1²
= 2²π ( d1=4 cm ,r1= 2 cm)
=4π
A2= π r2²
= 3²π
=9π
A1/A2 = 4π/9π
4/9
Ratio is 4:9

Answer 2

r1 = 2 cm
r2= 3 cm

area of circle 1= π r1²
= π x (2)²
= 4π

area of circle 2 = π r2²
= π (3)²
= 9π

area 1/area 2 = 4π/9π

area 1 / area 2 = 4/9

answer