Please help
The engine displacement of an automobile is the volume through which the piston moves from high to low position. If an engine has n cylinders, the displacement is D =pi*(bore/2)^2 • stroke • n, where the bore is the diameter of the cylinder and stroke is the length of the piston's travel.
1 If bore = r/2 and stroke = h, simplify the expression, D, in terms of r and h for 8 cylinders.
2 If the bore is 4 inches, the stroke is 3.4 inches, and the engine has four cylinders, what is the displacement? Round your answer to the nearest tenth of a cubic inch.