In triangle XYZ, the measure of angle X is 30° greater than the measure of angle Y and angle Z is a right angle. Find the measure of ∠Y.
∠Y = 30°
Let ∠Y = y, ∠X = y + 30°, ∠Z = 90°. Then y + (y + 30) + 90 = 180 ⇒ 2y + 120 = 180 ⇒ y = 30°.