Sphere
A sphere is a round ball, like a basketball or a baseball or a planet:
It is a solid 3dimensional figure where all points on it's surface are the same distance
from the center of the figure.
If you have a sphere whose radius is R, then
its volume (V) is: V = 4R^{3}/3
and its surface area (A) is A = 4R^{2}
Here is a problem for you (use your calculator):
 The radius of a basketball is 4.5 in. call this r_{1}
 The radius of a baseball is 1.25 in. call this r_{2}
 What is the volume of a basketball? v_{1} = ____________ cu. in.
 What is the volume of a baseball? v_{2} = _____________ cu. in.
 What is the ratio of the volume of a basketball to the volume of a baseball?
Ratio = ^{v1}⁄_{v2} = ____________ / ______________ = ______________
This is how many baseballs fit inside a basketball!
