Question 668503
Hard to visualize this one, but I'll give it a shot.

Let the point E be the the point where AB and CD bisect each other. (Maybe this is what the picture looks like)

So we have that AE is congruent to line CE. Since AB bisects CD then CE and ED are congruent. Similarly, since CD bisects AB then AE and EB are congruent. We have that AE ~= CE and AB ~= BE and CE ~= ED, so that proves that EB ~= ED.  

(Note that the ~= sign is really the congruent sign in this case, so be careful.)