Question

If the radius of a sphere is doubled, then find the percentage increase in its surface area

Answer 1

Let the radius be r

Surface Area = 4 pi *r^2


New Radius = 2r

New Surface Area = 4 * pi (2r)^2

= 4 * pi *4 r^2

= 16 pi *r^2

New Area = 4 * Original Area