Two-dimensional shapes like polygons have both interior and exterior measurements. One of the main external measurements of a polygon is its perimeter, which is the length around the polygon calculated by adding the lengths of its individual sides. Polygons are either regular or irregular. Regular polygons are so named because all sides are equal in length, while irregular polygons can have sides of varying lengths. Finding the perimeter of an irregular polygon involves calculating the number and lengths of its sides.
Instructions
-
-
1
Determine the polygon's number of sides. For this example, let the polygon be a heptagon, which has seven sides.
-
2
Measure each side with measuring tape or a ruler. In this example, the seven sides measure 2 inches, 2.5 inches, 2.5 inches, 3 inches, 1.5 inches, 2 inches and 1.5 inches.
-
-
3
Add the measurements of the sides to calculate the perimeter of the polygon. Concluding this example, adding together the measurements from the previous Step provides a perimeter total of 15 inches.