Question

In figure, O is the centre of the circle. Find ∠BAC.

Answer 1

Given: ∠AOB = 80° and ∠AOC = 110° 

Therefore, ∠AOB +∠AOC +∠BOC = 360° [Completeangle]

Substitute given values, 

80° + 100° + ∠BOC = 360° 

∠BOC = 360° – 80° – 110° = 170° 

or ∠BOC = 170° 

Now, by degree measure theorem 

∠BOC = 2∠BAC

170° = 2∠BAC 

Or ∠BAC = 170°/2 = 85°