Interior and Exterior Triangle Angles Calculator

Interior angles of a triangle are angles found inside the shape. According to the triangle angle sum theorem, sum of interior angles of a triangle always equals 180°:

a + b + c = 180°

For example, if you were trying to calculate an unknown interior angle a, you would utilize the triangle angle sum theorem in the following way:

• a = 180° - b - c (in degrees)
• a = π - b - c (in radians)

Keep on reading to learn about the definition of the exterior angle of a triangle!

What is the definition of the exterior angle of a triangle? If you were to extend any side of a triangle, the angle outside the triangle, adjacent to an interior angle, is an exterior angle of a triangle. Each triangle has six exterior angles, and two angles at each vertex are equal in value.

To find exterior angles of a triangle, you can use the exterior angle theorem. The exterior angle theorem states that the exterior angle is equal to the sum of the triangle's two opposite interior angles.

For instance, if you wanted to calculate the exterior angle d, you would use the following formula:

d = a + b

The sum of exterior angles of a triangle always adds up to 360°, while the sum of interior angles of a triangle equals 180°.

Using the interior and exterior triangle angles calculator is very straightforward!

Just enter two of any interior angles of the triangle, and the calculator will determine all remaining unknown values of interior and exterior angles.

Don't forget to change units of measurement for angles as per your convenience!

If you find the interior and exterior triangle angles calculator helpful, check out other related tools:

• Triangle angle calculator;
• Classifying triangles calculator;
• Triangle sum theorem calculator; and
• Exterior angles of a triangle calculator.