Perimeter is the total distance around the outside of a shape, found by adding the lengths of all its sides. It is measured in ordinary length units, not square units, because it is a distance rather than an area.
Math Dictionary / Perimeter
Perimeter
Perimeter is the total distance around a two-dimensional shape.
GeometryGrade 3Grade 4Grade 5Grade 6Grade 7GEDSATACT
What it means
Add all side lengths to find perimeter.
Also called: distance around
Examples
| A rectangle with sides 5 and 3 has perimeter 16 |
| A triangle perimeter is the sum of its three sides |
| Perimeter uses length units |
Common mistake
Do not multiply length by width for perimeter; that finds area.
Try one
Question: What is the perimeter of a square with side length 6?
Show answer
24.