This document is a lesson on slopes of lines. It defines slope as rise over run and includes examples of finding the slope of different lines using the slope formula. It discusses how to identify if lines are parallel, perpendicular, or neither based on their slopes. Specifically, parallel lines have the same slope and perpendicular lines have slopes that multiply to -1. There are also examples of graphing lines and determining if they are parallel, perpendicular, or neither based on their slopes. The document concludes with assigning homework problems on finding slopes and classifying lines.