|| || || || || || external image clip_image003.gif || Lesson Plan
Title of Lesson: Parallel Lines and Angle Relationships
Date: 2/5/11 Timeframe of Lesson: 3-4 days
Author(s): Brad Borchardt
School District: Medford Public Schools
Campus: Medford High School
Subject Area(s): Math
Grade Level(s)/Course: 9-12, Geometry
State Standards
Subject Specific:
Congruence G-CO
Experiment with transformations in the plane
1. Know precise definitions of angle, circle, perpendicular line, parallel
line, and line segment, based on the undefined notions of point, line,
distance along a line, and distance around a circular arc.
2. Represent transformations in the plane using, e.g., transparencies
and geometry software; describe transformations as functions that
take points in the plane as inputs and give other points as outputs.
Compare transformations that preserve distance and angle to those
that do not (e.g., translation versus horizontal stretch).
Technology Specific: http://dpi.wi.gov/imt/itlstfst.html
B. Information and Inquiry
Stated Objective(s)
Students will identify angle names and measures when parallel lines are cut by a transversal. Students will use CABRI geometry software to construct parallel lines, observe angle relationships, and report on their discoveries.
Procedures for Lesson
Day one is about getting familiar with the names of the angle pairs formed when two lines are cut by a transversal. We will do different learning activities in class to work on memorizing these terms. Day two we will head to the computer lab. The first five minutes are spent giving a brief introduction/tutorial on the software and then the students get a few minutes to do a few guided activities that are really just getting them familiar with the functions and commands of CABRI. Students then construct two lines cut by a transversal and review the names of the special angle pairs. For the “light bulb” moment, students drag one of the lines so that it is parallel to the other and observe what happens with the angles. They record their observations. Day three we compare observations with some group and class discussions and move forward with written practice in finding angle measures.
Assessment or Evaluation
This activity is great for some discovery learning but students will need to review and practice often to carry to long term memory. I will give small quizzes daily for the next two weeks to make sure students understand, providing feedback and instruction along the way.
For an extension of these angle relationships with parallel lines, students are given the opportunity to examine some of them at work in quadrilaterals such as parallelograms and trapezoids.

Technology Resources: 28 computers with CABRI geometry software either networked or on machines

Other Resources: