**Surface area** is the total area of the surface of a three-dimensional figure.

The surface area of a prism can be found by adding the areas of its faces.

First, find the area of each different-sized face.

There are two 4.5-foot by 2-foot faces, two 1-foot by 2-foot faces, and two 4.5-foot by 1-foot faces.

4.5 ft × 2 ft = 9 sq ft |
| 1 ft × 2 ft = 2 sq ft |
| 4.5 ft × 1 ft = 4.5 sq ft |

Now, add the areas of the faces. Remember there are two of each size.

(2 × 9 sq ft) + (2 × 2 sq ft) + (2 × 4.5 sq ft) = 31 sq ft