Question

If the surface area of a sphere is 900 pi, then its radius is

Answer 1

The surface area of a sphere is computed as follows:

`A=4\pi r^2`

where r is the radius. Substituting with A = 900π

`\begin{gathered} 900\pi=4\pi r^2 \\ (900\pi)/(4\pi)=(4\pi r^2)/(4\pi) \\ 225=r^2 \\ \sqrt[]{225}=r \\ 15=r \end{gathered}`