McGraw-Hill's Top 50 Skills For A Top Score: ASVAB Reading and Math

Skill 49 Calculate the Volume and Surface Area of Solids

You have reviewed area, which is the amount of space enclosed by the sides of a flat (two-dimensional) shape. The next step is to consider volume—the amount of space a solid object takes up in three dimensions.

A square has two dimensions, length and width. But if you add the third dimension of height (sometimes called depth), the square becomes a cube, as shown in the figure below. While a square has only one side, a cube has six sides with equal areas and equal perimeters.

If you add the third dimension of height to a rectangle, it becomes a solid object called a prism, which looks like ...