# What do the interior angles of a polygon have to add up to?

##### 2 Answers

See below.

#### Explanation:

The sum of interior angles of a polygon is equal to

where

Occours that the number of triangles is equal to the number of sides minus

The final formula is

Examples.

A triangle has

A quadrilateral has

A heptagon has

To determine the sum of the internal angles of a polygon, take the number of sides on the polygon, subtract 2 and multiply by 180 degrees.

#### Explanation:

A triangle has three sides.

The sum of the internal angles of a triangle is 180 degrees.

A quad lateral has four sides.

The sum of the internal angles of a square is 360 degrees.

A pentagon has 5 sides.

The sum of the internal angles of a pentagon is 540 degrees.

A hexagon has six sides.

The sum of the internal angles of a hexagon is 720 degrees

A heptagon has seven sides.

The sum of the internal angles of a heptagon is 900 degrees.

and so on!