Question

Find the surface area of a ball with 30 cm. radius.

Answer 1

Surface area of a sphere  = 4πr ^2.

Rarius (r ) = 30 cm.

Substitute r = 30 and π = 3.14 in 4πr  ^2.

Surface area of a ball = 4 * 3.14 * (30)^2

                                    = 12.56 * 900

                                    = 11304 cm ^2.

Therefore, Surface area of a ball is 11304 cm ^2.