Parallels and Transversal
You can move the pink points below to modify the diagram in real time. That is the only reason why they are pink (it has no other significance).
Make conjectures about the angles formed about the angles formed by two parallels and a transversal. You should specifically be thinking about PAIRS of angles where each angle is formed by unique parallels (e.g. one angle has the 'top' parallel as a side and the other in the pair has the 'bottom' parallel as a side).