Question

Finding the Measure of an Exterior Angle
Side XY of triangle XYZ is extended to point W, creating a linear pair with ∠WYZ and ∠XYZ.

Triangle X Y Z. Point W extends from side X Y. Angle Z is 36 degrees, angle Y is x degrees, and exterior angle W Y Z is 100 degrees.

What is the value of x?
64
80
100
180

Answer 1

80

Explanation: The exterior angle at Y (100°) equals the sum of the two remote interior angles, X + Z. So X = 100 - 36 = 64. Then X + Y + Z = 180 → 64 + x + 36 = 180 → x = 80.