Let O be the center of circle, OP = 25 cm (given)
Let T be the any point on the circle, then PT = 24 cm
To Find: Radius of the circle
From Figure:
OT ⊥ PT
In right ∆OPT,
By Pythagoras Theorem:
OP2 = OT2 + PT2
252 = OT2 + (24)2
625 = OT2 + 576
OT = 7
Radius of the circle is 7 cm.