Interior Angles And Exterior Angles Calculator. Conjectures In Geometry Exterior Angles. An exterior angle of a triangle is equal to the sum of the opposite interior angles.
An exterior angle of a triangle is equal to the sum of the opposite interior angles. First determine the number of sides. The exterior angles taken one at each vertex always sum up to 360.
Another way to calculate the exterior angle of a triangle is to subtract the angle of the vertex of interest from 180.
Determine the total sum of the interior angles using the formula A n-2180. 1n n - 2 180 or n - 2 180 n. A 360 N. Side Length a a 2r tanπn 2R sinπn Inradius r r 12a cotπn R cosπn Circumradius R R.