The radius of a circle is 8 cm. Calculate the length of a tangent drawn to this circle from a point at a distance of 10 cm from its centre.
OP = 10 cm, radius OT = 8cm
As PT is tangent to the circle and OT is the radius of the circle, OT is perpendicular to PT.
In triangle OTP,
OT2 + PT2 = OP2
82 + PT2 = 102
PT2 = 100 - 64
PT2 = 36
PT = 6 cm