# Perimeter review

Review the basics of perimeter and try some practice problems.

## What is perimeter?

Perimeter is the distance around the outside of a two-dimensional shape.

The perimeter of the shapes below is shown in .

*Want to learn more about the concept of perimeter? Check out this video.*

## How do we calculate the perimeter of a shape?

To find the perimeter of a shape, we add all of the shape's side lengths.

### Example 1:

**What is the perimeter of the trapezoid?**

We can find the perimeter by adding all of the side lengths.

### Example 2:

**What is the perimeter of the regular pentagon?**

We can find the perimeter by adding all of the side lengths.

All sides of a

*regular*pentagon are the same length.*Want to learn more about calculating perimeter? Check out this video.*

## Practice set 1: Calculate perimeter

*Want to try more problems like this? Check out these exercises:*

Find perimeter when given side lengths

Find perimeter by counting unit squares

## Practice set 2: Challenge items

*Want to try more problems like this? Check out these exercises:*

Find a missing side length when given perimeter

Perimeter word problems