U1L6 Construction Techniques 4: Parallel and Perpendicular Lines

In this lesson, students use previous constructions to create new constructions. This provides an example of a more general theme of learning—that discoveries build on one another and lay the foundation for new knowledge. The subsequent sections and units will guide students through a process of establishing a theoretical foundation and building new knowledge on itself within the framework of transformational geometry. Students make use of the structure that two circles of the same radius that go through each other’s center can be used to construct perpendicular lines to think strategically about how to construct a line perpendicular to a given line that goes through a given point not on the line (MP7). As students continue to apply the method for constructing a perpendicular line to construct a parallel line, they are engaging in repeated reasoning (MP8). This activity includes lesson summary videos and practice problems

By JOEL NELSON