Want more ideas and freebies?
Get my free resource library with digital & print activities—plus tips over email.
Join for free resources →Get the Lesson Materials
Rigid Transformations Reflections Guided Notes & Doodles | 8th Grade Geometry
$4.25
Overview
- Standard: CCSS 8.G.A.3
- Unit: 8th Grade → Unit 5: Transformations
- Grade: 8th Grade
Get the Lesson Materials
Rigid Transformations Reflections Guided Notes & Doodles | 8th Grade Geometry
$4.25
Learning Objectives
After this lesson, students will be able to:
- Graph figures on coordinate planes after reflections over the x-axis, y-axis, and the line y=x
- Write rules for reflections across the x-axis, y-axis, and the line y=x
- Write coordinate points for preimages and images for figures undergoing reflections over the x-axis, y-axis, and the line y=x
- Apply the concept of reflections to real-life situations and explain their significance
Prerequisites
Before this lesson, students should be familiar with:
- Graphing points on a coordinate plane
- Identifying the x-coordinate and y-coordinate of a point
- Knowledge of basic algebraic expressions and equations (optional, but helpful)
Materials
- Pencils
- Colored pencils or markers
- Guided notes
Key Vocabulary
- Rigid transformation
- Reflection
- X-axis
- Y-axis
- Line y=x
- Coordinate plane
- Preimage
- Image
Procedure
Introduction
As a hook, ask students why reflections are important in real life. For example, you can ask them how reflections are used in mirror images or in designing symmetrical art pieces.
Use the first page of the guided notes to introduce the concept of rigid transformations. Have students visualize the concept by having them trace reflections of fun objects, pumpkin, emoji, and triangles, across different lines of reflections. Walk through the key points of the topic, such as identifying the line of reflection and understanding how the preimage and image are related.
Then, following the guided notes, start introducing the rules of reflections across the x-axis, y-axis and the line y=x. Help students visualize the relationship between the preimage and image, and explain how the line of reflection changes the coordinates of the points.
Have students practice using the examples on the second page of the guided notes.
Based on student responses, reteach concepts that students need extra help with. If your class has a wide range of proficiency levels, you can pull out students for reteaching and have more advanced students begin work on the practice exercises.
Practice
Have students practice reflection examples using the maze on the third page of the guided notes. Walk around to answer student questions.
Fast finishers can dive into the color by number activity, the 4th page of the guided notes, for extra practice. You can assign it as homework for the remainder of the class.
Real-Life Application
Bring the class back together, and introduce the concept of real-world applications of reflections. Explain that reflections can be seen in many different aspects of our daily lives, from mirrors to water surfaces to architecture. Use the last page of the guided notes to have students read through a detailed examples of how reflections are used in architecture.
Encourage students to share their own experiences and examples of reflections they have encountered in their lives.
Having discussed the real-life applications, you can now move on to the next activity and allow students to apply their understanding of reflections through graphing on coordinate planes.
Extensions
Additional Self-Checking Digital Practice
If you’re looking for digital practice for reflections, try my Pixel Art activities in Google Sheets. Every answer is automatically checked, and correct answers unlock parts of a mystery picture. It’s incredibly fun, and a powerful tool for differentiation.
Here’s a reflection activity to explore:
Additional Print Practice
A fun, no-prep way to practice reflections is Doodle Math — they’re a fresh take on color by number or color by code. It includes multiple levels of practice, perfect for a review day or sub plan.
Here's a reflection activity to try:
FAQs
Rigid transformations are transformations that preserve the shape and size of a figure. There are four types of rigid transformations: translations, rotations, reflections, and dilations.
A reflection transformation is a type of rigid transformation that flips a figure over a line called the line of reflection. It produces a mirror image of the original figure.
To reflect a figure across the x-axis, you need to take each point of the original figure and move it the same distance above or below the x-axis. (x, y) -> (x, -y)
To reflect a figure across the y-axis, you need to take each point of the original figure and move it the same distance to the left or right of the y-axis. (x, y) -> (-x, y)
To reflect a figure across the line y=x, you need to swap the x and y coordinates of each point in the original figure. (x, y) -> (y, x)
To determine the rules for reflections, you need to observe the changes that occur to the coordinates of the original figure after the reflection. The rules can be different for each type of reflection (across x-axis, y-axis, or y=x).
Reflections have many real-life applications, such as in architecture, art, physics, and engineering. They are used to create symmetrical designs, study light and sound waves, and analyze structural stability.
You can practice reflections on coordinate planes by using graph paper and plotting the original figure. Then, apply the reflection rules to each point and plot the reflected image. Repeat this process for different figures and lines of reflection to gain more practice.
Using guided notes and doodles can be beneficial in learning reflections because they provide a structured and interactive way for students to engage with the material. They help students organize their thoughts, make connections, and retain information more effectively. Additionally, the visual and hands-on nature of doodling can enhance creativity and engagement in the learning process.