Question

Which sets of values can be the measures of the exterior angles of a triangle? 120°, 110°, 130° 35°, 103°, 122° 123°, 87°, 220° 120°, 120°, 120° 123°, 157°, 90°

Answer 1

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°

Explanation:

Answer 2

The values are :

• we khow that the sum of a triangle angles is 180°
• the sum of each set exterior and interior angle is 360°
• so 360+360+360-180 = 900 is the sum of exterior angles of a triangle
• we can see no set can satisfy this condition