In an isosceles triangle ABC, AB = AC, XY || BC. If ∠A = 30°, the ∠BXY = ?

Answer: Option D

$$\begin{array}{rl}& \text{If }\angle A=30^{\circ }\\ & \text{Then }\angle ABC=\angle ACB=\frac{{180}^{\circ }-{30}^{\circ }}{2}=75^{\circ }\\ & \angle BXY=180^{\circ }-\angle ABC\\ & =180^{\circ }-75^{\circ }\\ & =105^{\circ }\end{array}$$