# How to Find the Perimeter of a Pentagon

Looking for the perimeter of a pentagon requires you to focus on the outside of the shape and not what it contains. A pentagon is a polygon, which is a closed two-dimensional shape constructed from straight lines. A polygon can be regular, which means each of its sides measures the same, or irregular, where the sides are different lengths. A polygon's perimeter -- the combined length of its sides -- measures its borders. You can find the perimeter of both regular and irregular polygons through individual measurements combined with simple math.

• Ruler

## Instructions

• 1

Measure each side of the five sides of the pentagon. For example, suppose the five sides measure 2 inches, 3 inches, 4 inches, 3 inches and 2.5 inches.

• 2

Add the lengths of the five sides together. In this example, the sum of the five sides equals 14.5 inches.

• 3

Multiply the length of one side by 5 if the pentagon is a regular pentagon. For an example, multiplying a side length of 3 inches by 5 equals 15 inches.

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## Resources

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