The volume of a sphere is given by the equation 
, where r is the radius.
We are given the diameter of the sphere, but recall that the diameter is twice the radius:
. So the radius is half of the diameter: 
.
Half of 8 cm is 4 cm.
We substitute this for r in the equation and we use 3.14 for <span>π.</span>
We are given the diameter of the sphere, but recall that the diameter is twice the radius:
Half of 8 cm is 4 cm.
We substitute this for r in the equation and we use 3.14 for <span>π.</span>