Which statement correctly defines volume?

• A. The area of the surface.
• B. The amount of space inside a three-dimensional object.
• C. The distance around a shape.
• D. The space inside a two-dimensional object.

Answer: (B)

Volume is about how much space a three-dimensional object occupies. It measures the amount of space inside the object, like how much water would fill it. For a rectangular prism, you multiply length × width × height to find the volume, so a box that is 2 by 3 by 4 units holds 24 cubic units of space. Units are cubic (like cubic centimeters or liters) because you’re counting in three dimensions.

The other ideas mix up different concepts: the area of a surface describes size in two dimensions, not inside space. The distance around a shape is its perimeter, which is about the boundary, not the inner space. The space inside a two-dimensional object would be called area, since a flat shape has no thickness.