In this inquiry lesson, students will be investigating the questions, What is the relationship between the slopes of two perpendicular lines?; What is the relationship between the slopes of two parallel lines?; and What is the relationship between the slopes of two intersecting lines that are not perpendicular? Students will take pictures of parallel, perpendicular, and intersecting lines in the real world; they will draw parallel, perpendicular, and intersecting lines on coordinate planes; they will calculate slopes; and they will discover how the slopes of each set of lines relate to each other, generalizing to a conclusion about slope relationships. This is a structured inquiry lesson, so students are given the questions for investigation and the experimental procedure, but they will carry out the experiments and come to data-driven conclusions on their own.
Download the Slope of Parallel and Perpendicular Lines lesson plan.