Enter the triangle angles to calculate the exterior angle or calculate the exterior angle of any polygon.

Exterior Angle Calculator

Use the triangle exterior angle theorem or calculate exterior angles for a regular polygon.

Triangle Exterior Angle Theorem
Regular Polygon Exterior Angle

Enter any valid combination. The calculator can solve from both remote interior angles, from the adjacent interior angle, from the exterior angle, or from one remote angle plus the adjacent interior or exterior angle.

Triangle Results

For a regular polygon, enter any one value below. The calculator solves the number of sides, each exterior angle, each interior angle, the central angle, and the angle sums.

Regular Polygon Results

Exterior Angle Formula (Regular Polygon)

The following formula is used to calculate each exterior angle of a regular polygon (all sides and angles equal).

A = 360^\circ / N
  • Where A is the exterior angle (in degrees) for a regular polygon
  • N is the number of sides of the polygon

To calculate each exterior angle of a regular polygon, divide 360° by the number of sides. (For any convex polygon, the sum of one exterior angle at each vertex is 360°.)

Exterior Angle Definition

An exterior angle of a polygon is the angle formed by one side of the polygon and the extension of an adjacent side at a vertex.

Exterior Angle Example

How to calculate an exterior angle?

  1. First, determine the number of sides.

    Count the number of sides of the polygon being analyzed. For this example we will look at a regular hexagon that has six sides.

  2. Next, calculate the exterior angle.

    Using the formula, we find the exterior angle to be 360/6 = 60 degrees.

FAQ

What is an exterior angle?

An exterior angle of a polygon is the angle formed by one side of the polygon and the extension of an adjacent side at a vertex.