In the given figure, O is the centre of the circle and ∠AOB = 150°. Then, ∠ACB = ?

1. 75°

2. 105°

3. 85°

4. 115°

In the given figure, ABCD is a cyclic quadrilateral. The measure of its greatest angle is :

1. 135°

2. 140°

3. 150°

4. 160°

In the given figure, O is the centre of the circle and ∠BDC = 36°. The measure of ∠ACB is :

1. 36°

2. 54°

3. 72°

4. 46°

ABCD is a cyclic quadrilateral such that AC is a diameter of the circle. If ∠BAC = 58° and ∠DAC = 65°, then ∠BCD is equal to :

1. 57°

2. 123°

3. 90°

4. 60°