The radius of one sphere is twice as great as the radius of a second sphere.

Find the ratio of their surface areas.

3 answers

4π(2r)^2 / 4πr^2 = 4
the square of the radius ratio
Find the surface area of an orange with a 3'' radius.
The formula is above. Plug in r=3.

We will assume a smooth, rather than a dimpled, surface :-)