From a point Q, the length of the tangent to a circle is 24 cm and the distance of Q from the center is 25 cm. The radius of the circle is
Given that PQ = 24 cm and OQ = 25 cm.
To find OP, apply Pythagoras theorem for △OPQ.
OP2+QP2=OQ2
OP2+242=252
OP2=625−576=49
⇒OP=7 cm