1. The document discusses using angles formed by a transversal to show that lines are parallel using the parallel line theorems. 2. It provides an example of finding values of x and y that make two sets of lines parallel using the same-side interior angle theorem. 3. It also shows a proof that lines CD and BE are parallel given that angle BE bisects angle DBA and angle 3 is congruent to angle 1 using alternate interior angles.