What is the formula for the volume of a prism?

• A. V = base area * height
• B. V = length * width
• C. V = base area
• D. V = base area + height

Answer: (C)

Volume is found by multiplying the area of the base by the distance between the bases. The base area tells you how much footprint the prism has, and the height tells you how far that footprint is carried to create the third dimension. Think of slicing the prism into many thin slabs parallel to the base; each slice has the same base area, and stacking them gives total volume equal to base area times height.

For a rectangular base with area 12 square units and height 5 units, the volume is 12 × 5 = 60 cubic units.

Using only the base area would give area, not volume, and length × width is just the base area for a rectangle. Adding height is not dimensionally correct for volume.