What is the volume of a sphere with a 21 cm diameter

The formula for the volume of a sphere is 4/3*pi*r^3 where r is the radius.

So firstly, let's find the radius, which is quite simply half the diameter.

21/2 = 10.5.

So now we have the radius let's plug it into the formula:

4/3*pi * (10.5) ^3 = 4850cm^3 to 3 sf.

R = 1/2 d = 1/2 (21) = 10,5 cm

V = 4/3Πr³ = 4/3 x 22/7 x (10,5) ² = 4850 cm³