1. In the given figure, O is the centre of a circle and ∠AOC = 120°. Then, ∠BDC =

2. In the given figure, O is the centre of a circle in which ∠OAB = 20° and ∠OCB = 50°. Then, ∠AOC =

3. In the given figure, O is the centre of a circle in which ∠AOC = 100° side AB of quadrilateral OABC has been produced to D. Then, ∠CBD =

4. In the given figure, O is the centre of a circle and ∠OAB = 50°. Then, ∠BOD =

5. In the given figure, ABCD is the cyclic quadrilateral in which BC = CD and ∠CBD = 35°. Then, ∠BAD =

6. In figure, ΔABC is an equilateral triangle and ABDC is a quadrilateral then ∠BDC =

7. In figure, sides AB and AD of a quadrilateral ABCD are produced to E and F respectively. If ∠CBE = 100°, then find ∠CDF.

8. In figure, O is the centre of a circle and ∠AOB = 140°, then ∠ACB =

9. In figure, O is the centre of a circle and ∠AOB = 130°, then ∠ACB =