Question

If circumferences of two circles are in the ratio `3:1`, what is the ratio of their areas?

Answer 1

The ratio of areas of two circles will be `9:1`

Explanation:

The formula for circumference `C` of a circle is `2pir`

Hence `Cpropr`, `2pi` being constant

The formula for area `A` of a circle is `pir^2`

Hence `Apropr^2`, `pi` being constant

Hence, as ratio of circumferences of two circles is `3:1`

ratio of areas of two circles will be `3^2:1^2` or `9:1`