Description: Learn about parallel lines, transversals, and the angles they form. Created by Sal Khan. If those two things are true, and when they're not the same line, they never intersect and they can be on the same plane, then we say that these lines are parallel. If we drew our coordinate axes here, they would intersect that at a different point, but they would have the same exact slope. And what I want to do is think about how angles relate to parallel lines.*Teacher Advisor is 100% free.