Surface Area of a Sphere and Hemisphere

POINT

A sphere has surface area 4πr². A hemisphere has curved area 2πr²; for its total surface area, include the circular base πr², giving 3πr².

EXAMPLE

Find the surface area of the sphere with radius 5 cm and the total surface area of the hemisphere with radius 6 cm.

Practice

Find the surface area of each solid.

Sphere — radius: 3 cm

\(36\pi\,\mathrm{cm}^2\)

Sphere — radius: 7 cm

\(196\pi\,\mathrm{cm}^2\)

Hemisphere — radius: 4 cm

\(48\pi\,\mathrm{cm}^2\)