Triangle WXY is isosceles. ∠YWX and ∠YXW are the base angles. YZ bisects ∠WYX.m∠XYZ = (15x)°. m∠YXZ = (2x + 5)°. What is the measure of ∠WYX?

Because YZ bisects ∠WYX, the full vertex angle ∠WYX measures 2(15x) = 30x°. The triangle is isosceles with equal base angles, and ∠YXZ is one of them, so each base angle is (2x + 5)°. Using the triangle angle sum gives 30x + 2(2x + 5) = 180, so x = 5. Therefore ∠WYX = 30(5) = 150°, choice D.

AI-written and checked against the verified answer.