A, B and C are three points on a circle. The tangent at C meets BN produced at T. Given … the angle subtended by AB at the centre…
Answers:
Join BC. Let O be the centre of the circle. Join OA and OB.
In △BCT, △ACT,
∠BTC = ∠ATC = 36˚
∠ACT = ∠ABC = 48˚
∠BAC = ∠ACT + ∠ATC
= 48˚ + 36˚ = 84˚
∴ ∠BCA = 180˚ – (∠ABC + ∠BAC)
= 180˚ – (48˚ + 84˚) = 48˚
∴ ∠BOA = 2∠BCA
= 2 × 48˚
= 96˚