If the radius of a circle is increased by 1% then the area of that circle increases by what percent?
If the radius of a circle is increased by 1% then the area of that circle increases by what percent? Correct Answer 2.01%
Previous values = 10 unit Present radius = (10 + 10 × 1%) = 10.1 Previous area = πr2 = π×102 = 100π Present area = π(10.1)2 = 102.01π Increase of area = (102.01π - 100π) = 2.01π Precent of increase = (2.01π100π×100)% = 2.01%