Parallel and Perpendicular Lines
In this lesson, students will:
□ Graph equations using slope-intercept form
□ Apply basic geometric knowledge of parallel and perpendicular
□ Discover that parallel lines have the same slope
□ Discover that perpendicular lines have opposite reciprocal slopes
Time: 30-45 minutes
Description of Lesson:
Teacher gives each student (up to 32) a handout.
Students graph their equation.
Teacher leads class in a discussion about what “parallel” means. […lines that never intersect.]
Students are instructed to get up and find someone who has a line that is parallel to theirs and complete Activity 1, then return to their seats. [A timer could be set for 5-7 minutes.]
Teacher leads class in a discussion about what “perpendicular” means. […lines that intersect at 90°.]
Students are instructed to get up and find someone who has a line that is perpendicular to theirs and complete Activity 2, then return to their seats. [A timer could be set for 5-7 minutes.]
As a group (trio or table of 4) students are instructed to procede through activities 3, 4 and 5 at the pace of their group.
■ There are 32 different equations for 32 kids to graph (one each). 4 equations of each of the following slopes:
1/2, –2, 4/3, -3/4,2/3, – 3/2, 5 and -1/5
■ Students should easily be able to find one line that is parallel to their equation during activity 1 and one equation that is perpendicular to theirs during activity 2.
■ Should you find and error or have a question, please email firstname.lastname@example.org