An exterior angle of a triangle equals the sum of the two interior angles not next to it. If those two measure 50 and 60 degrees, what is the exterior angle?

Correct answer to question 83 (Mathematics Knowledge): 110 degrees

Method

The exterior angle theorem gives 50 + 60 = 110 degrees directly. Checking the long way agrees: the third interior angle is 180 - 110 = 70, and the exterior angle beside it is 180 - 70 = 110.