According to the Exterior Angle Theorem, the measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles. Note that one of these angles is a right angle, so it has a measure of 90^(∘). Let's write an equation applying this theorem.
6x +90 =y
As we can see, in order to find the measure of the exterior angle, we need to know the value of x. It can be found by using the Triangle Angle-Sum Theorem. Since the given triangle is right, the acute angles are complementary. In this case, 6x and 5x+2 sum up to 90.
