Since A and B are end points of the longest chord of the circle,AB is itsdiameter. Hence ∠ACB = 900 as angle inscribed in a semicircle is a right angle.Thus we have Δ ABC right angled at C.Given, AC = AO = 3 cm
⇒BC=AB2−AC2​=62−32​=27​
⇒BC=33​units∴ Perimeter of Δ ABC=AB+BC+AC=6+33​+3=9+33​ units
