Lesson plan

# Lesson 16: More Symmetry

teaches Alabama State Standards Geo-22.b.
teaches Alabama State Standards Geo-22.
teaches Alabama State Standards Geo-21.
teaches Arizona State Standards G.G-CO.A.3
teaches Common Core State Standards HSG-CO.A.3 http://corestandards.org/Math/Content/HSG/CO/A/3
teaches Common Core State Standards MP6 http://corestandards.org/Math/Practice/MP6
teaches Georgia State Standards MGSE9-12.G.CO.3.
teaches Kansas State Standards G.CO.1d.
teaches Kansas State Standards G.CO.1c.
teaches Kansas State Standards G.CO.1b.
teaches Kansas State Standards G.CO.1a.
teaches Kansas State Standards G.CO.1.
teaches Ohio State Standards G.CO.3.b.
teaches Ohio State Standards G.CO.3.
teaches Pennsylvania State Standards CC.2.3.HS.A.1.

# Lesson 16: More Symmetry

In this lesson, students continue to examine cases in which applying a certain rigid motion to a shape doesn’t change it, and this time, students will be looking at rotation symmetry. For a shape to have rotation symmetry, there must be an angle for which the rotation takes the shape to itself. Students have opportunities to use precise language in the warm-up as they identify different types of symmetry (MP6). Students continue using precise language in their justifications of symmetry throughout the activities.

Lesson overview

• 16.1 Warm-up: Which One Doesn't Belong: Symmetry (5 minutes)
• 16.2 Activity: Self Rotation (20 minutes)
• Includes "Are you Ready for More?" extension problem
• 16.3 Activity: Parallelogram Symmetry (10 minutes)
• Lesson Synthesis
• 16.4 Cool-down: Mystery Quad (5 minutes)

Learning goals:

• Describe (orally and in writing) the rotations that take a figure onto itself.

Learning goals (student facing):

• Let’s describe more symmetries of shapes.

Learning targets (student facing):

• I can describe the rotations that take a figure onto itself.

Required materials:

• Copies of blackline master
• Geometry toolkits
• Sticky notes
• Tools for creating a visual display

Required preparation:

• If there are not enough leftover shapes from the previous lesson, prepare more copies of the blackline master from Self Reflection so that each student in each group gets copies of the shape their group will investigate in Self Rotation.

Glossary:

• rotation symmetry - A figure has rotation symmetry if there is a rotation that takes the figure onto itself. (We don't count rotations using angles such as $$0^\circ$$ and $$360^\circ$$ that leave every point on the figure where it is.)
• Access the complete Geometry Course glossary.

Standards:

• This lesson builds on the standards:CCSS.HSG-CO.A.1MS.G-CO.1MO.G.CO.A.1CCSS.HSG-CO.A.4MS.G-CO.4MO.G.CO.A.4

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