|AP| = |PB| = \(x\) (The perpendicular to a chord bisects the chord if drawn from the center of the circle.) From ∆OPB Using Pythagoras theorem ⇒ \(13^2 = 12^2 + x^2\) ⇒ \(169 = 144 + x^2\) ⇒ \(169 - 144 = x^2\) ⇒ \(x^2 = 25\) ⇒ \(x = \sqrt25 = 5 cm\) ∴ Length of the chord |AB| = \(x + x = 5 + 5 = 10 cm\)