The document discusses several theorems and properties for proving when two lines are parallel, including: 1) If corresponding angles formed by a transversal intersecting two lines are congruent, then the lines are parallel. 2) If alternate interior angles or alternate exterior angles formed by a transversal are congruent, then the lines are parallel. 3) If consecutive interior angles formed by a transversal are supplementary, then the lines are parallel. It also provides an example of...
