In quadrilateral ABCD, the diagonal AC divides it into two congruent triangles, that is, △ABC≅△CDA.
a. (i) Prove that AB=CD.
b. (ii) Prove that AB∥CD.
c. (iii) Hence show that ABCD is a parallelogram.
d. (iv) If AB=5cm and BC=3cm, find the perimeter of ABCD."