Question

If the radius of a circle is increased by 50 %, what will be the percent increase in the

circumference of the circle? (Circumference 2*pi *r)

Answer 1

If the radius is increased by 50 per cent,
then R = r+ r/2
= 3r/2 = 1.5r
thus, increase in circumference = 2 pi r = 2 x pi x 1.5 r
= 3 pi r.
Thus initial c = 2 pi r, final c = 3 pi r.
thus increase percent = change in c/ initial c x 100 = 1/2 x 100 = 50 percent.
Thus, the circumference will also increase by 50 %