Question

∠A, ∠B, ∠C are three angles of a triangle. If ∠A – ∠B = 15°, ∠B – ∠C = 30°, then ∠A, ∠B and ∠C are

पर्याय

• 80°, 60°, 40°

• 70°, 50°, 60°

• 80°, 65°, 35°

• 80°, 55°, 45°

Answer 1

80°, 65°, 35°

Explanation:

∠A + ∠B + ∠C = 180°  .....(i)

(∠B – ∠C) – (∠A – ∠B) = 30° – 15°

⇒ 2∠B – ∠A – ∠C = 15°  ......(ii)

 By adding (i) and (ii),

⇒ ∠B = 65°

∠A – ∠B = 15°

⇒ ∠A = 15° + 65° = 80°

∠C = ∠B – 30° = 65° – 30° = 35°