Parallel and Perpendicular Lines https://www.youtube.com/watch?v=BPgM3q6e-bk&t=100sMathematics problems often deal with parallel and perpendicular lines. Since these are such popular lines, it is important that we remember some information about their slopes.Parallel Lines: (same slope!)Parallel lines are marked with "feathers" to show that they are … [Read more...] about Parallel and Perpendicular Lines