##
* *Reflection: Connection to Prior Knowledge
Rocking Rotations - Section 1: Lesson Beginning

To begin the activity for this first part of class notes (on page 1), I asked students to use graph paper, pencil and scissors to create a triangle that is congruent to the given triangle, YUM. Instead of providing more directions on how students could complete this, I found that most of my class traced their triangle and then cut out a congruent new triangle, which we named Y'U'M'. This act of tracing and then cutting out two triangles that were congruent really cemented for my students that the pre-image and image were congruent shapes (see this Beginning Student Example)

Then, as students rotated the image (triangle Y'U'M') it was easy for them to see that the new shape would be an isometry. Furthermore, I found that while working together, my students were able to discover a rule for how to rotate 90 CCW. It was exciting to see my students drawing from prior knowledge and applying this to generalize a rule for this type of transformation (see this second, Beginning Student Example)

*Connection to Prior Knowledge: Making Math Hands-On*

# Rocking Rotations

Lesson 2 of 7

## Objective: SWBAT identify and draw rotations of polygons on the coordinate plane.

#### Lesson Beginning

*15 min*

Do Now: In this Do Now, students will ask students to first try and identify a rotation using a Yankee symbol. Teachers who do not live in New York may want to change this to another sports symbol. The second question will also ask students to review reflecting about the x and y-axis. This is a great time for teachers to review key vocabulary from previous lesson like pre-image, image and transformation.

Teachers can also review the agenda and objective for this lesson.

Introduction to New Vocabulary:

Before starting the middle of the lesson, teachers can review key vocabulary for this lesson, counterclockwise and clockwise as well as a movement (or rotation) of 90 degrees. The graphics of the cats will help to review this topic with students.

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#### Lesson End + Homework

*25 min*

Activity/Homework:

After completing in class examples, students should be encouraged to work in pairs or small groups on practice questions and a worksheet with examples, which can be found in student notes. Teachers can circulate and answer student questions. After giving students 15-20 minutes to work on this assignment, teachers can ask students to put their work on the board and then review these questions with the entire class. This is a great opportunity for teachers to reinforce vocabulary and also ask students some important summary questions like,

- How are rotations different from reflections?
- How do rotations change a pre-image?
- What transformations have we covered so far? Which have been the most challenging for you? Why?
- What is the definition of transformation?

Exit Ticket:

The Exit Ticket for this lesson reviews how to complete a rotation for CCW 90 and CCW 180. Please find the enclosed resources.

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Hey Stephanie,

I'd echo Tom's suggestions to make the do-now more open-ended and to provide more cases for students to perform the inductive reasoning.

Love the student notes. That's a really good resource to be able to hand to students. I wonder how exactly you use the transparencies or parchment

paper for the rotations and how you manage that. I also wonder about the R sub O, 90 notation you use starting on page 3...are students already

familiar with that? BTW, on p.3, second checklist item should say 180, I think.

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I wonder if you might include an opportunity for students to independently determine a rule for rotation about the origin starting from scratch. For example, Â determine a rule for rotation 90 degrees clockwise about the origin.

Finally, do you use dynamic geometry software? If so, could you use it to enhance the lesson in any way?

Once again, good lesson. Gave me some ideas. Thanks.

| 3 years ago | Reply

Stephanie, nice lesson.

A couple of questions.

Do now: I was wondering about the 'yes/no' question. Â I would recommend changing that to some kind of open-ended question. Â For example: a. Â Describe how you can create the image of the Yankees logo from the pre-image using reflections.' Â (It can be done. Â It takes two reflections.) Â b. Does 'reflection' seem like the best word to describe this transformation?

I really like the way you use the student's own work as part of their scaffolded notes. Â

Since you are developing the rule for rotating an object CCW 90 degrees inductively, it would be nice for students to see a few more examples. Â What about making 2 or more versions of the notes, each with a different figure to rotate. Â You could distribute the notes so that, say, every student in a team of 3-4 students has a different version. Â Students can still work together to help one another or check the work of their peers. Â And, now they will see 2-3 additional cases to prove the rule. Â

Good luck with this lesson!

Tom

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| 3 years ago | Reply##### Similar Lessons

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- UNIT 1: Introduction to Geometry: Points, Lines, Planes, and Angles
- UNIT 2: Line-sanity!
- UNIT 3: Transformers and Transformations
- UNIT 4: Tremendous Triangles
- UNIT 5: Three Triangle Topics
- UNIT 6: Pretty Polygons
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- UNIT 11: Trig Trickery
- UNIT 12: Finally Finals

- LESSON 1: Introduction to Transformations and Reflections
- LESSON 2: Rocking Rotations
- LESSON 3: Translations are Terrific
- LESSON 4: Compositions, Not Just a Notebook
- LESSON 5: Dilation Nation
- LESSON 6: Isometry, Survival of the Fittest and Review
- LESSON 7: Project and Assessment for Transformation Unit