ABC is a triangle inscribed in a circle with center O. If angle AOC = 130 and angle BOC = 150, find angle ACB.
In triangle AOC,
AO = OC (radii of same circle)
..., angle OCA=angle OAC,
Now, angle AOC = 130o
So, angle OCA=angle OAC =(180-130) / 2 = 250
Follow the same steps in triangle OBC.
You will get angle OCB =150 .
Now add angle ACO and angle OCB = 25 +15 = 400.
Hope this helps!