Download Parallel Lines

Parallel Lines: Teacher Notes
Overview
In this activity students investigate the angle relationships that occur when a transversal
cuts through two parallel lines.
Important Mathematical Ideas
 The angles formed by a transversal crossing two parallel lines have special
relationships - some angles are equal and some are supplementary.
Prior Knowledge
 Understanding geometry concepts (e.g., parallel lines, transversal, alternate angles,
corresponding angles, co-interior angles, vertically opposite angles).
 Applying angle relationships for intersecting lines (e.g., supplementary angles,
complementary angles, vertically opposite angles) to determine angle measures.
 Applying angle relationships for parallel lines and transversals (e.g., alternate,
corresponding, co-interior and vertically opposite angles) to determine angle
measures.
 Using symbols that represent geometric attributes and properties .
Common Misconceptions
 Applying properties of parallel lines to lines that are not parallel.
Information to Support/ Enhance/ Extend Learning
 Students are asked to keep a journal for each unit in the course. It should contain
notes of important mathematical ideas with examples and new vocabulary.
 ePortfolio may be used for these journal entries.
 Students can make individual choices whether this is a paper or digital personal
resource.
 Consider a variety of formats as alternatives to journal entries (e.g., student note,
pair/share, group discussion, exit card, poster, electronic posting).
 Develop a Word Wall and continue it throughout the unit as new vocabulary and
terms arise that require clarification (e.g., parallel lines, transversal, alternate angles,
corresponding angles, co-interior angles, vertically opposite angles).
Minds On
Task 1: Job Connection and Journal Prompt and Sample Response
1) Visit Jobs with Geometry website to find careers that use parallel lines.
1) Identify two careers that use parallel lines.
Two careers that would use parallel lines are construction workers and bridge
builders.
2) Give examples of how parallel lines are used in these careers.
o Parallel lines would be used in framing walls for houses so that the walls would
be straight.
Grade 9 Applied Blended Learning: Unit 8 Activity 2
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Parallel Lines: Teacher Notes
o The posts of a bridge would have to be parallel for the bridge to be level.
3) Find and post pictures that demonstrate how parallel lines are used in these careers.
Action
Task 2: Parallel Lines Investigation
 Students will:
o use Parallel and Non-Parallel Lines GSP sketch to investigate properties of
parallel lines - alternate, corresponding and co-interior angles
o record their findings on the Parallel Lines Record Sheet
 Consider using a Think/Pair/Strategy for the investigation.
 To provide a visual cue consider co-developing an Anchor Chart for parallel line
angle properties as a whole-class activity.
 Solutions should include:
o correctly measured angles
o the relationship between the corresponding angles, alternate angles and cointerior angles
o screenshots of the four sets of “F-pattern” angles, two sets of “Z-pattern” angles
and two sets of “C-pattern” angles
 Common Error:
o incorrect angles measured
Check Your Understanding
 Students will:
o examine four types of angles pairs formed in a picture
o identify vertically opposite, corresponding, alternate and co-interior angles
o check answers with solutions provided
Grade 9 Applied Blended Learning: Unit 8 Activity 2
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Parallel Lines: Teacher Notes
Consolidation
Task 3: Review Angle Properties
 Angle Properties (Math Song) video reviews angle properties including those for
parallel lines.
Check Your Understanding
Students will:
 answer three missing angle problems
 check with provided solutions
Task 4: Assignment 1: Angles in Real Life
 Posted with unit.
 See sample solution in the Teacher Notes posted on the Virtual Learning.
Environment (vLE).
Task 5: Assignment 2: Parallel Lines
 Posted with unit.
 See sample solution in the Teacher Notes posted on the Virtual Learning.
Environment (vLE).
Task 6: Student Reflection
 Students are asked to reflect on their understanding of this topic.
 These reflections can be used as assessment for learning to help determine next
steps for individual students.
Grade 9 Applied Blended Learning: Unit 8 Activity 2
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