In the given figure, AB is tangent to the circle with center O. If OCB is a straight line segment, the angle BAC is :

1. 40°

2. 55°

3. 35°

4. 20°

For the three circles with centers A, B and C and radii 5 cm, 2 cm and 6 cm respectively.

Assertion (A) : To find the perimeter of the triangle ABC, add the radii of given three circles.

Reason (R) : The required perimeter is the product of sum of radii by 2.

1. A is true, R is true

2. A is true, R is false

3. A is false, R is true

4. A is false, R is false

In the given figure, O is center of the circle and PQ is a tangent. If angle OAB = x; the measure of angle ABP; in terms of x, is :

1. x

2. 180° - 2x

3. 90° + x

4. 90° - x