I need to do a proof from this: <link removed>
Did you notice that the angles numbered <1 and <5 are
corresponding angles formed when lines AB and FD are cut by transversal EB.
If you can show that <1 and <5 are congruent, then you can use the postulate (or theorem, depending on your text) which says that if two lines are cut by a transversal so that a pair of corresponding angles are congruent, the lines are parallel.
You have two triangles...one pair of angles in those triangles is GIVEN congruent.
Another pair of angles are formed by a couple of sets of perpendicular lines. What kind of angles are formed by perpendicular lines? That should allow you to establish that the angles in this second pair are congruent.
AND...if two angles of one triangle are congruent to two angles of another triangle, what can you say about the THIRD pair of angles in those triangles?
(The third pair of angles, by the way, would consist of the angles we're interested in....angles 1 and 5.)
So...there it is, an outline for your two-column proof. I hope you can follow that outline and write the proof yourself.