In the given figure, O is the centre of a circle, ∠OAB = 30° and ∠OCB = 40°. Calculate ∠AOC.

In the given figure, O is the centre of the circle and ∠AOB = 110°. Calculate:

(i) ∠ACO

(ii) ∠CAO.

In the given figure, AB ∥ DC and ∠BAD = 100°. Calculate :

(i) ∠BCD

(ii) ∠ADC

(iii) ∠ABC.

In the given figure, ∠ACB = 52° and= ∠BDC = 43°. Calculate

(i) ∠ADB

(ii) ∠BAC

(iii) ∠ABC.