Question

What is the exact volume of a sphere with a diameter of 36 in.?

Answer 1

The volume of a sphere:
$V=\frac{4}{3} \pi r^3$
r - the radius

The diameter is twice the radius.
$d=36 \ in \\ r=\frac{36}{2} \ in = 18 \ in \\ \\ V=\frac{4}{3} \pi \times 18^3=\frac{4}{3}\pi \times 5832=\frac{23328}{3} \pi=7776\pi \ [in^3]$

The exact volume of the sphere is 7776π in³.