Volume of a right circular cylinder is

• A. 2 pi r h
• B. pi r^2 h
• C. pi r h^2
• D. pi d^2 h

Answer: (B)

Volume is found by multiplying the base area by the height. For a right circular cylinder, the base is a circle with radius r, so its area is πr^2. Multiplying by the height h gives πr^2h, which is the volume. The other expressions don’t match the concept: 2πrh is the lateral surface area, not volume; πrh^2 would misuse height squared; and πd^2h uses diameter instead of radius (and would be missing the correct factor to convert from diameter).