In a triangle ABC, the measure of angle A is 40° less than the measure of angle B and 50° less than that of angle C. Find the measure of ∠A.
∠A = 30°
Let ∠A = x. Then ∠B = x + 40, ∠C = x + 50. Sum = x + (x + 40) + (x + 50) = 180 ⇒ 3x + 90 = 180 ⇒ x = 30°.