Description : For spreading the message 'Save Environment Save Future' -Maths 9th
Last Answer : In △ABC, we have ∠A + ∠B + ∠C = 180° (Since, sum of the angles of a △ is 180°) ⇒ 1/2∠A + 1/2∠B + 1/2∠C = 180°/2 ⇒ 1/2∠A + ∠1 + ∠2 = 90° ∴ ∠1 + ∠2 = 90° - 1/2∠A .. ... using (i) ] ⇒ ∠BOC = 180° - 90° + 1/2∠A ∴ ∠BOC = 90° + 1/2∠A Environmental care, social, futuristic.