LET AB is chord and point M is the midpoint of AB, O is the centreGiven, OM = 15 CM and Radius OB = 17 cmIn ΔOMBUsing Pythagoras theorem⇒ (OB)2 = (OM)2 + (MB)2⇒ 172 = 152 + (MB)2⇒ MB = √(289 – 225) = 8As, we know, AB = 2 MBAB = 2 × 8 = 16 cm