Question

If a sphere has a radius of 2 cm what is the approximate surface area of the sphere

Answer 1

The formula for the surface area of a sphere is $SA=4 \pi r^{2}$
If your radius is 2, then filling in that formula looks like this:
$SA=4 \pi ( 2^{2} )$ or $16 \pi$.  If you leave your answer in terms of pi, which is the exact answer, you're done.  But if you multiply pi in, your surface area is SA = 50.264 square cm.