ABCD is a parallelogram
diagonals AB bisect BD at E
In triangle AED and CEB, DAE = BCE (alternate interior angles)
AD = CB
ADE = CBE (alternate interior angles)
AED CEB (ASA)
Hence, AE = CE and ED = EB
Thus, the diagonals of a parallelogram bisect each other.
Hence, segment AE is congruent to segment CE