The volume of a sphere is 36π ft3. What is the radius of the sphere? Use the formula V =

4

3

πr3 to find your answer.

V = (4/3) pir^3

36pi=v

36pi = (4/3) pir^3

divide both sides by pi

36 = (4/3) r^3

multiply both sides by 3/4 to clear fraction (4/3 times 3/4=12/12=1)

108/4=r^3

27=r^3

cube root both sides

3=r

radius=3ft

V=4/3 (πr³) ⇒r=∛ (3V/π4) = (∛3v / 4π)

r=∛ (3 (36π ft³) / 4π) =

r = (∛108π ft³ / 4π) = (∛27 ft³) = 3 ft

Answer: radius=3 ft