EngageNY
Representing Reflections with Transformations
In the 16th lesson plan in the series of 32 the class uses the concept of complex multiplication to build a transformation in order to reflect across a given line in the complex plane. The lesson plan breaks the process of reflecting...
CCSS Math Activities 
Smarter Balanced Sample Items: 8th Grade Math – Target G
Transform the thinking of transformations with six sample items that illustrate the first four standards in the eighth grade geometry domain. Items use the coordinate plane to transform figures and analyze the relationship of the figures...
Curated OER
Reflecting Reflections
A triangle rests in quadrant two, from which your class members must draw reflections, both over x=2 and x=-2. This focused exercise strengthens students' skills when it comes to reflection on the coordinate plane.
Mathed Up!
Mixed Transformations
Viewers learn how to identify and perform a variety of transformations with a video that provides seven items on transformations. Pupils demonstrate their understanding of dilations, reflections, rotations, and translations. The video...
Inside Mathematics
Aaron's Designs
Working with transformations allows the class to take a turn for the better. The short assessment has class members perform transformations on the coordinate plane. The translations, reflections, and rotations create pattern designs on...
Curated OER
Congruent Segments
The task, should your class decide to take it, is to list a series of reflections that transfer a line segment from one position to another. 
Illustrative Mathematics
Reflections and Isosceles Triangles
Geometers explore symmetries of isosceles triangles by using rigid transformations of the plane. They complete four tasks, including congruence proofs, which illustrate the relationship between congruence and rigid transformations. The...
EngageNY
Mid-Module Assessment Task: Grade 8 Module 2
It's time for a concept check! Check for student understanding over the three types of rigid transformations. The assessment follows the first 10 lessons in this series and to test pupils' proficiency of these concepts. Individuals...
EngageNY
The Geometric Effect of Some Complex Arithmetic 1
Translating complex numbers is as simple as adding 1, 2, 3. In the ninth lesson in a 32-part series, the class takes a deeper look at the geometric effect of adding and subtracting complex numbers. The resource leads pupils into what it...
EngageNY
Similarity
Use the coordinate plane to show two figures are similar. The lesson incorporates congruence transformations and dilations to move a figure on to another figure. Pupils determine that if a similarity transformation exists...
Curated OER
Why Does SAS Work?
Your geometry learners are guided by questions that help them use the language of reflections to explain the Side-Angle-Side congruence between two triangles in this collaborative task. Given a sample solution, declaring the...
Curated OER
Point Reflection
Use this task as an exit ticket for your eight graders during the geometry unit. All they need to do is identify the coordinates of a point reflected over y=2000. 
Curated OER
Symmetries of a Quadrilateral II
Learners investigate the symmetries of a convex quadrilateral in a collaborative activity. Rigid motion and complements are explored as learners analyze different cases of reflections across a line.
Curated OER
Congruent Rectangles
Very simply, geometers examine a pair of rectangles on graph paper and find a translation and rotation to demonstrate their congruence. A couple of questions follow to stimulate critical thinking about other possibilities.
Curated OER
Symmetries of a Quadrilateral I
Learners examine the properties of quadrilaterals from the point of view of rigid motion. Different types of quadrilaterals are characterized by their symmetries, so learners explore the symmetries of a described quadrilateral to...
Oswego City School District
Regents Exam Prep Center: Working With Line Reflections
This Regents Prep site contains numerous problems concerning line reflections. Each multiple choice problem contains a short explanation.
Khan Academy
Khan Academy: Determine Reflections (Advanced)
Given two figures on the coordinate plane, find the formal definition of the reflection that takes one figure to another. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive...
Khan Academy
Khan Academy: Advanced Reflections
Find the reflection that maps a given figure to another and draw the image of a reflection. The lines of reflection in this exercise have a wide range of slopes. Students receive immediate feedback and have the opportunity to try...
Khan Academy
Khan Academy: Reflect Points
In this exercise, students practice performing reflections on a coordinate plane. Students receive immediate feedback and have the opportunity to watch a video, get hints, or try questions repeatedly.
Khan Academy
Khan Academy: Practice: Reflect Points
In this set of questions, students practice using an interactive tool to reflect images on a Cartesian grid. Includes hints.
Oswego City School District
Regents Exam Prep Center: Intuitive Notion of Line Symmetry and Plane Symmetry
Definitions are provided line of symmetry, line symmetry, and plane symmetry, and several nice examples are provided that illustrate these definitions.
Khan Academy
Khan Academy: Congruence and Transformations
Given a pair of figures in the coordinate plane, try to map one onto the other and determine whether they are congruent. Includes examples of glide reflections. Students receive immediate feedback and have the opportunity to try...
Oswego City School District
Regents Exam Prep Center: Reflection in a Line
This site gives some examples of line reflection transformations. Includes coordinate graphs to show reflections of lines and shapes.
Khan Academy
Khan Academy: Reflect Shapes
Given a figure and a definition of a reflection, draw the image. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
