What is the volume of the sphere with a diameter of 14 cm use 3.14 for pi

Volume of sphere formula is:

V = 4/3 Pi r^3
It just is - you have to remember that.

We don't have radius, we have diameter.  Radius is just half the diameter - so 7cm

V = 4/3 Pi (7)^3

V = 4/3 (3.14) (343)

V = 1436 cm^3  - remember its centimeters cubed because we are working with volume