Cornell University
Cornell University: Straightness and Symmetry
This site, part of a planned Geometry textbook, involves real-world applications with symmetry and reflection using pictures and graphs.
Mathigon
Mathigon: Geometry: Symmetry
This lesson focuses on symmetry including reflectional symmetry, rotational symmetry, and palindromes. It defines each, gives examples, and practice activities.
National Council of Teachers of Mathematics
The Math Forum: The Four Types of Symmetry in the Plane
This Math Forum site gives visual examples of rotation, translation, reflection, and glide reflection with background information about each. Also gives problems to work on concerning symmetry.
Smithsonian Institution
Smithsonian Learning Lab: Turn About's Fair Play! Mirrors and How They Reflect
Teachers can download this teaching package that looks at light and symmetry through the use of mirrors. Students will enjoy the nine mirror challenges, along with the hands-on activities described in the lessons. Teachers will...
CK-12 Foundation
Ck 12: Geometry: Symmetry and Tessellations Study Guide
[Free Registration/Login may be required to access all resource tools.] Provides a brief overview of the different types of symmetry and of how to tessellate a shape.
Khan Academy
Khan Academy: Symmetry of 2 D Shapes
Analyze various shapes according to their reflective and rotational symmetries.
Mocomi & Anibrain Digital Technologies
Mocomi: What Is Symmetry in Math
Defines symmetry, line of symmetry, point symmetry, and gives examples.
Windstream
Ojk's Precalculus Study Page: Reflections and Symmetry
An introduction to the various types of symmetries that can occur in the graphs of functions. Uses vertical, horizontal, and oblique reflections as a means of recognizing symmetries.
Illustrative Mathematics
Illustrative Mathematics: G Co Symmetries of a Quadrilateral Ii
There is exactly one reflection and no rotation that sends the convex quadrilateral ABCD onto itself. What shape(s) could quadrilateral ABCD be? Explain. Aligns with G-CO.A.3.
Shodor Education Foundation
Shodor Interactivate: Lesson: Tessellations Geometry and Symmetry
This lesson plan deals with tessellations and their geometric concepts. Upper elementary and middle school students will also explore polygons, symmetry, analyze patterns and explore the role of mathematics in nature and culture.
Shodor Education Foundation
Shodor Interactivate: Lesson: Translations, Reflections, and Rotations
This upper elementary and middle school lesson plan introduces a variety of motion geometry concepts such as translations, reflections, and rotations. Lots of interactive support for students.