It certainly looks like AB and DC are parallel, but I think it is more logical to use the angles directly. Angles AEB and DEC are vertex angles so they are equal. Since we are given that angles 2 and 4 are equal we may say that the angles 1 and 3 are equal since the sum of interior angles of a triangle is 180 degrees. ie. 180 = angle 2 + angle AEB and 180 = angle 4 + angle DEC. Can you finish this up?
-Dan