In triangle ABC, if angleA + angleB = 65? and angleB + angleC = 140? , find the measures of all angles in the triangle. Share with your friends Share 0 Sushant Ranjan answered this Dear Student, We know that, ∠A + ∠B +∠C = 180° Angle sum propperty⇒∠A + ∠B + ∠C = 180°⇒65° + ∠C = 180°⇒∠C =180° - 65° = 115°now,∠B +∠C = 140°⇒∠B +115° = 140°⇒∠B = 140° - 115° = 25°Now,∠A + ∠B = 65°⇒∠A + 25° = 65°⇒∠A = 65° - 25° = 40 0 View Full Answer