I is the incentre of ∆ ABC. If ∠ABC = 60°, ∠BCA

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I is the incentre of ∆ ABC. If ∠ABC = 60°, ∠BCA = 80°, then the ∠BIC is

1. 90°
2. 100°
3. 110°
4. 120°

Correct Option: C

According to question , we draw a figure of ∆ ABC whose I is the incentre

Given , ∠ABC = 60°, ∠BCA = 80°
∠ABC = 60° ⇒ ∠BCA = 80°
∠ABI = ∠IBC = 30°
∠ACI = ∠ICB = 40°
In ∆ BIC,
∴ ∠BIC + ∠ICB + ∠IBC = 180°
∠BIC = 180° – 30° – 40° = 110°