r=a

The volume of a sphere is equal to 43 times Pi π times the radius cubed.

43⋅π⋅(radius)3

Substitute the value of the radius r=a into the formula to find the volume of the sphere. Pi π is approximately equal to 3.14.

43⋅π⋅a3

Combine 43 and π.

4π3⋅a3

Combine 4π3 and a3.

4πa33

Find the Volume sphere (a)