In this exercise we want to explain if it is possible to prove that the backrest and footrest of the lounging beach chair are parallel. Let's begin by making a graph where we focus on the relevant parts of the chair.
If two lines in a plane are cut by a transversal so that a pair of alternate interior angles is congruent, then the lines are parallel.
In our case, the assumptions of the theorem are satisfied. Therefore, we can conclude that the lines of the footrest and the backrest of the lounging beach chair are parallel.
