The height of a cylinder is 12 inches and the radius is 3.5 inches. What is the approximate volume of the cylinder?

V = pi*r^2*h

V = pi*(3.5)^2*12

V = pi*12.25*12

V = pi*147

V = 147pi   exact volume in terms of pi

V = 461.8141200777 is the approximate volume (use a calculator here)

The units for the volume are in cubic inches

Side note: If you use pi = 3.14, then you'll get an approximate volume of 147*pi = 147*3.14 = 461.58 which is a bit off from the other value we got earlier due to the fact pi = 3.14 is not as accurate as using the calculator's internal value of pi.