Which expression correctly expresses the volume of a rectangular prism?

• A. V = L + W + H
• B. V = L * W
• C. V = L * W * H
• D. V = (L + W) * H

Answer: (C)

Volume is the amount of space inside a 3D shape. For a rectangular prism, you can think of filling it by layers: the base is a rectangle with length L and width W, whose area is L × W. The prism’s height is H, so you stack H of those base “slices.” The total space inside is base area times height, giving V = (L × W) × H, which simplifies to V = L × W × H.

Expressions that add dimensions, like L + W + H, just sum edge lengths and don’t measure space. Using only the base area, L × W, gives the footprint, not the full volume. And (L + W) × H mixes lengths in a way that doesn’t reflect stacking identical base areas through the full height.