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Question Find ∠B and ∠C, if A is the centre of the circle.
In ∆BAC AB = AC = Radius of the circle. Let ∠ABC = ∠ACB = x (angles opposite to equal sides are equal) Then, x + x + 120° = 180° (∵ Sum of all the angles in a triangle is 180°) ⇒ 2x = 180° – 120° ⇒ 2x = 60° ⇒ x = 30° Hence ∠B = ∠C = 30°