Perimeter

Perimeter is the distance all the way around a shape. Imagine walking along the edge of a playground. The total distance you walk is the perimeter. We find perimeter by adding up the lengths of every side. It is measured in regular units like inches, feet, or meters.

How to Find Perimeter

Finding the perimeter is simple addition. If a rectangle has sides of 5, 3, 5, and 3, the perimeter is 16. For a square, just multiply one side by 4. Every side counts when you measure the perimeter. Some shapes with many sides take longer to add up.

Perimeter in Real Life

Perimeter is useful in many jobs. A farmer uses it to know how much fence they need. A runner knows how far one lap is around a track. You might use it to pick a frame for a picture. Builders use perimeter when they plan new houses. It shows up in many places every day.

Fun Facts

• The perimeter of a standard soccer field is about 360 meters.
• A circle's perimeter is called its circumference.
• The word perimeter comes from Greek words meaning 'around measure.'

Did You Know?

The Great Wall of China is more than 13,000 miles long. If you walked along its perimeter, it would take years.