Supplementary Angles That Are Not A Linear Pair

     My grandparents' house has a small roof over the front porch. The two parallel lines are formed by one side of the main house and another side of the jutting out part. The line along the porch roof is a transversal to those two parallel lines. Because of consecutive interior angles, we know that angle one and angle two are nonadjacent supplementary angles. Architecturally, the two parallel lines are parallel because they have to both be perpendicular to the ground in order for the house to stand. The line along the small roof has to protect the porch and let water drip from it, thus allowing it to be slanted and not perpendicular to the parallel lines. Many objects in the real world have two parallel lines cut by a transversal, such as window frames, but those have 90 degree angles. My picture/example of nonadjacent supplementary angles is unique, as angles one and two are not congruent.