Draw two concentric circles of radii 2 cm and 5 cm. Take a point P on the outer circle and construct a pair of tangents PA and PB to the smaller circle. Measure PA.
1) Draw a circle with radius 2 cm and centre O.
2) Draw another circle with radius 5cm and centre O.
3) Take a point P on the circumference of the larger circle and join P to O.
4) Now taking OP as diameter and draw another circle which intersections the smaller circle at two points let say A & B.
5) Join A to P and B to P.
Hence required tangents are AP and BP.