How to Prove the Angle Sum Property of a Triangle
Angle Sum Property of a TriangleTheorem 1: Prove that sum of all three angles is 180° or 2 right angles. Given: ∆ABC To prove: ∠A + ∠B + ∠C = 180° Construction: Draw PQ || BC, passes through point A. Proof: ∠1 = ∠B and ∠3 = ∠C ……. (i) [∵ alt…