Question

A,B and C are three points on a circle with centre O such that angle BOC=30° and angle AOB=60° . If D is a point on the circle other than the arc ABC, find angle ADC

Answer 1

refer to ncert text book,u will see that theorem 10.8 governs the problem.
here it is given that angle BOC=30 and AOB=60
therefor,angle AOC=60+30=90
Now, acc. to theorem 10.8-
angle ADC=1/2AOC
Hope it helps........ : )