Given: Radius =25cm Length of chord =48cm Concept used: The perpendicular from the center of a circle to a chord bisects the chord. Pythagoras Theorem: Hypotenuse 2= Base 2+ Perpendicular 2 Calculation:
OA=OB=25cm (Radius of circle) AB=48cm PB=AB∕2=48∕2 Using the above concept PA=PB=24cm Applying Pythagoras theorem in △OPB , OB2=OP2+PB2 ⇒252=OP2+242 ⇒OP2=625−576 ⇒OP2=49 ⇒OP=7cm ∴ The length of perpendicular drawn from the centre of the circle to the chord is 7cm .