The equation for the surface area of a sphere is \(A=4 \pi r^{2}\)
So plug in 3 cm for radius "r"
\(A=4 \pi ( 3cm)^{2}\)
Simplify
\(A=4 \pi (9 cm^{2})\)
\(A=36 \pi cm^{2}\)
Depending on your teacher, they might want you to leave it like this or plug in 3.14 for \(\pi\)
So your answer is either
\(A=36 \pi cm^{2}\)
or
\(A=113.04 cm^{2}\)
