In the given figure, AB and CD are diameters of a circle with centre O. If ∠OBD = 50°, find ∠AOC.
It is given that, AB and CD are diameter with center O and `angleOBD = 50°`
We have to find `angle AOC`
Construction: Join the point A and D to form line AD
Clearly arc AD subtends`angle ABD = 50°` at B and `angleAOD` at the centre.
Since CD is a straight line then