In the adjoining figure, AC = BD. If ∠CAB = ∠DBA, then ∠ACB is equal to

1. ∠BAD

2. ∠ABC

3. ∠ABD

4. ∠BDA

In the adjoining figure, ABCD is a quadrilateral in which BN and DM are drawn perpendiculars to AC such that BN = DM. If OB = 4 cm, then BD is

1. 6 cm

2. 8 cm

3. 10 cm

4. 12 cm

In △ABC, BC = AB and ∠B = 80°. Then ∠A is equal to

1. 80°

2. 40°

3. 50°

4. 100°

In △PQR, ∠R = ∠P, QR = 4 cm and PR = 5 cm. Then the length of PQ is

1. 4 cm

2. 5 cm

3. 2 cm

4. 2.5 cm