Polygons:: Calculations

Below are some calculations relating to different types of polygons.

Sum of the angles in a polygon

To calculate the sum of a polygon, follow the following rule. We have listed the most common and easiest way below.

N= number of sides
            (n-2) x 180

Number of Diagonals

To calculate the number of diagonals, use the following rule:

n = number of sides

For your convenience, we have done some calculations for you. Below is a list of the diagonals for 4 polygons.

• Pentagon - 5 diagonals
• Hexagon - 9 diagonals
• Heptagon - 14 diagonals
• Octagon - 20 diagonals