Question: abcd is a cyclic quadrilateral whose diagonals ac and bd intersect at p?
Answer: Since abcd is a cyclic quadrilateral whose diagonal ac and bd intersect at p if ab = dc, our aim is to prove that triangle pas is congruent to triangle pdc ,pa=pb ,pc=pb ,ad is parallel to bc. ... In third part, we are given that diagonals are bisectors, so ABCD is a parallelogram, therefore AD║BC.