The formula for the volume of a sphere, V, in terms of its radius, r, is:
V = 4/3πr3
Example
Calculate the volume of the sphere shown below in cm3 to 3 sig. figs.
Answer
Diameter d = 8 cm
Radius r = 8 ÷ 2 = 4 cm
Volume = 4/3πr3 = 4 ÷ 3 x π x 43 = 268.08.... ≈ 268 cm3 (3 s.f.)