In ∆ ABC, ∠A + ∠B = 65°, ∠B + ∠C

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In ∆ ABC, ∠A + ∠B = 65°, ∠B + ∠C = 140°, then find ∠B.

1. 40°
2. 25°
3. 35°
4. 20°

Correct Option: B

According to question ,
Given , ∠ A + ∠ B = 65°
In ∆ ABC,
As we know that , ∠ A + ∠ B + ∠ C = 180°
∴ ∠ C = 180° – 65° = 115°
and ∠ B + ∠ C = 140°
⇒ ∠ B + 115° = 140°
∴ ∠ B = 140° – 115° = 25°