# Find the sum of the interior angle measures of the polygon.

A polygon is a closed two-dimensional figure that comprises three or more straight lines.

## Answer: The formula for calculating the sum of interior angles of a polygon is (n - 2) × 180°.

Let's look at some examples.

**Explanation:**

Let 'n' be the number of sides of a regular polygon.

The sum of interior angles of a polygon = (n - 2) × 180°.

For example,

The sum of interior angles of triangle = (3 - 2) × 180° [since a triangle is a 3 sided polygon, hence, n = 3]

= 180°

The sum of the interior angles of the square = (4 - 2) × 180° [since a square is a quadrilateral, hence, n = 4]

= 360°

The sum of the interior angles for the polygon with n = 10 will be,

= (10 - 2) × 180°

= 1440°