Which sets of values can be the measures of the exterior angles of a triangle? Click all that apply.

120°, 110°, 130°

35°, 103°, 122°

123°, 87°, 220°

120°, 120°, 120°

123°, 157°, 90°

The sum of the interior angles of any polygon is (n-2) * 180° (n being the number of sides) so for a triangle the sum of the interior angles is 180°. The sum of the interior and exterior angles is also 180°. To work out which sets are possible you subtract each number from 180° and then add all three answers together. If you get 180° then that set of numbers is possible. Using this method, you will find that the following sets can be the measures of the exterior angles of a triangle:

120°, 110°, 130°

120°, 120°, 120°