Question

given a circle with centre O, Q is a piont in the exterior such that OQ=2.5cm and the length of the tangent from Q to the circle is 2cm.What is the radius of the circle?

Answer 1

Answer:

Let AP be a tangent drawn from P to a circle with centre O such that AP = 24 cm and OB = 25 cm.

In right angled △ OAB,

OP

2

=OA

2

+AP

2

25

2

=OA

2

+24

2

OA

2

=49

OA=7 cm

Hence, the radius of circle is 7 cm.