# Surface area review

Review surface area and try some practice problems.

## What is surface area?

**Surface area**is the amount of space covering the outside of a three-dimensional shape.

## Finding surface area

To calculate surface area, we add the areas of all the faces of the three-dimensional figure.

*Want to learn more about finding surface area? Check out this video.*

### Example: Rectangular prism

**Find the surface area of the right rectangular prism shown below.**

Let's draw a net of the rectangular prism.

Each of the sides is a $4$ by $1.5$ rectangle.

The total area of both sides is $2 \cdot 6 = \blueD{12}$.

The bottom and the top are both $4$ by $5$ rectangles.

The total area of bottom and the top is $2 \cdot 20 = \greenD{40}$.

The back and the front are both $1.5$ by $5$ rectangles.

The total area of the back and the front is $2 \cdot 7.5 = \goldD{15}$.

Let's add the areas to find the surface area.

**The surface area of the rectangular prism is $67$ units$^2$.**