A chord of length 40 cm is drawn at a distance of 15 cm from the centre of a circle, then the radius of the circle will be :

1. 12 cm

2. 15 cm

3. 17 cm

4. 25 cm

In the figure, O is the centre of the circle and AC = BC = 3.5 cm. ∠ACO will be :

1. 60°

2. 80°

3. 90°

4. 100°

A chord of length 70 cm is drawn in a circle of radius 37 cm. The distance of the chord from the centre of the circle is :

1. 20 cm

2. 15 cm

3. 14 cm

4. 12 cm