Given : A circle with center O and radius OP=5cm
PQ is a tangent and OQ = 12 cm
We know that ∠OPQ = 90°
Hence in triangle OPQ
2=2+PQ2
[hypotenuse2 = Adj.side2+Opp.side2]
2 = 2+PQ2
PQ2 = -
PQ2 =
PQ = √