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Question
In the given figure, O is the centre of the circle. Tangents at A and B meet at C. If angle ACO = 30°, find: angle AOB
Solution
In the given fig, O is the centre of the circle and CA and CB are the tangents to the circle from C. Also, ∠ ACO = 30
P is any point on the circle. P and PB are joined.
To find : ∠AOB
Proof :
∴ ∠ ACB = 30° + 30° = 60°
∴∠ AOB + `∠`ACB = 180°
⇒ ∠ AOB + 60° = 180°
⇒ ∠ AOB = 180° - 60°
⇒ ∠ AOB = 120°
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