In the given figure, AC is a tangent to the circle with centre O. If ∠ADB = 55°, find x and y. Give reasons.

In two concentric circles, a chord of larger circle which is to smaller circle is bisected at the point of contact.

1. secant

2. tangent

3. chord

4. diameter

There are two tangents to a circle passing through a point lying outside the circle.

1. at least

2. at most

3. exactly

4. maximum

If two tangents are drawn from an external point to a circle, then the tangents are equally inclined to the line joining the point and the centre of the circle, i.e., the centre lies on the of the angle between the two tangents.

1. perpendicular

2. bisector

3. perpendicular bisector

4. none of these