MCS Lesson of the Week

Lesson Title: Oh My Polygon! Grade: 6 Strand: Geometry and Spatial Sense Learning Goal (Curriculum Expectations) Gr. 6 – classify and construct polygons and angles Reasoning and Proving – develop and apply reasoning skills to make and investigate conjectures and construct and defend arguments Representing – develop and apply reasoning skills to make and investigate conjectures and construct and defend arguments

Key Ideas - Geometric objects have properties that allow them to be classified and described in a variety of different ways - Understanding relationships between geometric objects allow us to create any geometric object by composing and decomposing other geometric objects ICT Standards:

Lesson Components Anticipated Student Responses Opportunities for ICT Integration Part 1: Minds On  What do we know about:  compare to benchmark angles  Use Notebook Flash file to Right angles o smaller than a right angle investigate angles and Acute angles  provide measurement ranges record findings Obtuse angles o between 0º and 89º Straight angles  compare to other types of angles  students could project their Reflex angles? o smaller than an obtuse angle notes Students use the Notebook Angle  describe the arms in comparison to other Types Flash file to describe the angles different angles using attributes and o the arms would be closer together geometric properties than those of a 90º angle

Part 2: Action Problem: Construct a polygon that has: o 3 different types of angles  Use PhotoBooth to share Geoboard or o at least 1 side with a length of 3 units grid paper solutions

Name and describe your polygon using geometric properties including lines of symmetry.

Students work independently, in pairs, or small groups.

Possible materials: Geoboards, grid paper, GSP, Smart Notebook

Part 3: Consolidation With the students, sort polygons according to the number of lines of symmetry.

IT Services: Teaching and Learning with Technology - Winter 2011 - http://community.elearningontario.ca MCS Lesson of the Week

Generalize: When does a polygon have zero lines of symmetry? Only one line of symmetry? What types of polygons have more lines of symmetry? Consider the number of sides, lengths of sides, angles.

Part 3: Highlights and Summary

Polygons can be described and sorted according to: o number of sides o length of sides o types of angles o lines of symmetry There are different ways of finding lines of symmetry. The more sides a regular polygon has, the more lines of symmetry there will be. The number of lines of symmetry in a regular polygon is always equal to the number of vertices.

Part 3: Practice How many lines of symmetry can a pentagon with 2 right angles have? Can a pentagon have more lines of symmetry? Explain and justify your solution.

IT Services: Teaching and Learning with Technology - Winter 2011 - http://community.elearningontario.ca