Explanation:
Circumference of a circle is C = 2π r.
Volume of a sphere is V = 4/3 π r³.
Use the circumference to find the radius. Then use the radius to find the volume.
Or, you can find volume as a function of radius:
r = C / (2π)
V = 4/3 π (C / (2π))³
V = 4/3 π (C³ / (8π³))
V = 1/6 C³ / π²
V = C³ / (6π²)