The volume of a cylinder is 441π in3. The height of the cylinder is 9 in. Calculate the diameter of the cylinder to the nearest tenth of a centimeter. Use the formula:
V = πr²h
Vcylinder = pi * r^2 * h
441 pi = pi * r^2 * 9 divide both sides by 9 pi
441/9 = r^2 take the positive root
21/3 = r = 7
So the diameter = 2 * r = 2 * 7 = 14 in
you know the volume, and formula.
441π = π r^2 * 9
So essentially r^2 * 9 = 441.
Isolate the variable.