The formula below shows the relationship between the volume (v), in cubic centimeters, of a cylinder and the radius (r) and height (h), in centimeters, of the cylinder. 
 v = πr2h
 The formula below shows the relationship between the diameter (d), in centimeters, of the circular base of the cylinder, and the radius, in centimeters, of the base. 
 d=2r
 1. Express the volume of the cylinder in terms of its diameter and height.