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∘