In figure, A, B, and C are three points on a circle with centre O such that ∠BOC = 300 and ∠AOB = 600. If D is a point on the circle other than the arc ABC, find ∠ADC (in degrees).
∠ADC = 12∠AOC (the angle subtended by an arc at the centre is double the angle subtended by it any point on the remaining part of the circle)
= 12 [∠AOB + ∠BOC]
= 12 [60∘+ 30∘]
= 45∘