Question

In the given figure, if AB is a tangent to the circle with centre O such that OB = 6 cm and ∠AOB = 60°, then the length of OA is :

How many tangents can be drawn from the point P on the outer circle to the inner circle in the given figure ?

PQ and PR are tangents to the circle of radius 3 cm and centre O. If length of each tangent is 4 cm, then perimeter of △ OQP is :

PQ is tangent to the circle centred at O. If OQ = 3 cm, PQ = 5 cm, then OP is equal to

In two concentric circles centred at O, a chord AB of the larger circle touches the smaller circle at C. If OA = 3.5 cm, OC = 2.1 cm, then AB is equal to