What are the equations for the surface area and volume of a sphere?
Surface Area: Four times pi times radius squared
Volume: (4/3) times pi times radius cubed.
Notice how the Surface Area is the derivative of the volume. This is not chance.
Area 4pir^2
volume 4/3pir^3
from http://freeabel.geom.umn.edu/docs/reference/CRC-formulas/
great link, Jimpy!