Analyze Math
Analyze Math: Reflection Across a Line
Reflect any point, line segment, triangle, or any other figure over one or two lines using this dynamic applet. Points and lines are entered by point-and-click rather than by typing equations or ordered pairs. A very neat exercise to...
Beacon Learning Center
Beacon Learning Center: Ask Hannah
This web lesson teaches students about symmetry in two-dimensional shapes.
University of South Florida
Fcat: Reflection: Teacher Notes
Students use the coordinate plane to investigate how reflections affect geometric shapes. Can be used by the student, but is also a great lesson plan idea for teachers.
Illustrative Mathematics
Illustrative Mathematics: 8.g Congruent Segments
Eighth graders are shown two line segments that are the same length and must describe a sequence of reflections that exhibits a congruence between them. Aligns with 8.G.A.2.
Alabama Learning Exchange
Alex: How Light Travels
In this lesson, the students will be experimenting to show how light shines in a straight line. They will also be experimenting to see how light reflects using mirrors. The students will be working in cooperative learning groups to carry...
Mathigon
Mathigon: Geometry: Rigid Transformations
This lesson focuses on rigid transformations, a specific set of rules that convert one geometric figure into another one. There are many different types of transformations, like reflections or rotations. It provides several practice...
Illustrative Mathematics
Illustrative Mathematics: 8.g Reflecting a Rectangle Over a Diagonal
In this task, 8th graders are presented with several rectangles that have diagonal lines through them and are placed on grids. They are asked to draw reflections and to discuss rectangles that are squares. Aligns with 8.G.A.
Shodor Education Foundation
Shodor Interactivate: Transmographer 2
Build your own polygon and transform it in the Cartesian coordinate system. Experiment with reflections across any line, rotations about any point, and translations in any direction.
Illustrative Mathematics
Illustrative Mathematics: 8.g Point Reflection
In this task, 8th graders are given the coordinates of a point and are asked to find the coordinates of its reflection across a line parallel to the x-axis. Aligns with 8.G.A.3.
Concord Consortium
The Concord Consortium: Molecular Workbench: Bunimovich Stadium
Watch as two particles move through a confined area. The emphasis is on their motion in a straight line until they encounter a barrier and are reflected off in a different direction.
Oswego City School District
Regents Exam Prep Center: General "Transformation" Vocabulary
This site offers a short discussion of transformations. The discussion has few pictures and expresses the transformations in terms of relative coordinates rather than pictures.
Math Is Fun
Math Is Fun: Reflection
Students learn about reflection. An activity, examples, tricks, and a definition are included.
Illustrative Mathematics
Illustrative Mathematics: G Co Origami Equilateral Triangle
The purpose of this task is to explore reflections in the context of paper folding. Each fold is associated with a line of reflection and understanding each step in the construction requires careful analysis of angles and of the...