A, B and C are three points on a circle such that the angles subtended by the chords AB and AC at the centre O are 80° and 120°, respectively. The value of ∠BAC is:
Answer & explanation
Correct answer: option 4
∠AOB + ∠AOC + ∠BOC = 360º
80º + 120º + ∠BOC = 360º
∠BOC = 160º
Angle made by an arc on centre is double to that made by same arc on circumference.
So, ∠BAC = \(\frac{∠BOC}{2}\)
= \(\frac{ 160º}{2}\)
= 80º