congruent lines: how do I prove DE congruent to DF?

[Motherof8]

Lines AB, CD, and EF are parallel and horizontal. They are intersected by 2 lines going downward, the second slanting downward to the right.
AC is congruent to CE. How do I prove that DE is congruent to DF?

[stapel_eliz]

Is the other "vertical" line actually vertical, or is it "slanty" as well? What letters indicate the intersections of these lines with the original three lines? Do these "vertical" lines relate at all to the points A, B, C, D, E, and F? Are A, C, and E all on the same ends (say, the left-hand end) of the original three lines?

There needs to be additional information. Otherwise, with only what is posted so far, it is fairly simple to draw a picture in which DF is most definitely not congruent to DE.