In quadrilateral ABCD the diagonals AC and BD meet at O such that AO=CO and BO=DO. The lengths of two sides are AB=6.5cm and BC=4.8cm.
(a) Prove that △AOB≅△COD.
(b) Prove that △BOC≅△DOA.
(c) Using the conclusions of (a) and (b), determine the lengths of CD and AD. Show all steps clearly.