Once again, I hate proofs so much.
One easy solution is to follow the common logic which is if two lines are both straight and equidistant from each other, SO THEIR PARALLEL, but since education these days asks us to write theses stupid "proofs" here's my attempt:
First off what must we prove to show that two lines are parallel??
Well, the first way is if the corresponding angles, the angles that are on the same corner at each intersection, are equal. If those angles are the same, then the lines are parallel. The second is if the alternate interior angles, the angles that are on opposite sides of the transversal and inside the parallel lines, are equal, then the lines are also parallel.
Well angles 1, 2, 3, 4, 5, 6, 7 and 8 are equal and also 90 degrees, thus the corresponding angles and alternate interior angles are all equal, which means that these two lines are parallel.
