In a triangle ABC, if ∠A + ∠C = 140° and ∠A

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In a triangle ABC, if ∠A + ∠C = 140° and ∠A + ∠B = 180°, then ∠A is equal to

1. 80°
2. 40°
3. 60°
4. 20°

Correct Option: C

Given that , ∠A + ∠C = 140° and ∠A + ∠B = 180°
In a ∆ ABC,
We know that , ∠A + ∠B + ∠C = 180°
⇒ ∠B + 140° = 180°
⇒ ∠B = 180° – 140° = 40°
∴ ∠A + 3 ∠B = 180°
⇒ ∠A + 3 × 40° = 180°
⇒ ∠A = 180° – 120° = 60°.