IM1 – G-CO-4 Lesson 2 Reflections Moving an Object In 2 Dimensions Mr. Deyo G.CO.4 Develop definitions of rotations, reflections, and translations in terms of angles, circles, perpendicular lines, parallel lines, and line segments.

Date: Title: IM1 – G-CO-4 Lesson 2 Reflections Learning Target By the end of the period, I will create a definition of reflection in 2 dimensions and apply that definition to a given object. I will demonstrate this by completing Four-Square Notes and by solving problems in a pair/group activity.

Home Work 1-2-3: 1) Class 4-Square Notes Put In Binder? 2) Section ______ 3) Section ______ TxtBk. Problems_________ Notes Copied on blank sheet Solved and Put in Binder? of paper in Binder? Table of Contents Date Description Date Due

Storm Check (Think, Write, Discuss, Report) Questions on which to ponder and answer: How are the two images similar? How are they different? How can these two images be related to math? IMAGE 1 IMAGE 2

Reflection Vocabulary Pre-Image Image Axis of Reflection

Vocabulary Acquisition Friendly Definition Sketch Wordwork Sentence DAY 2 1. Review word Friendly Definition Physical Representation 2. Draw a sketch DAY 1 Use Visuals Introduce the word Friendly Definition Physical Representation Use Cognates Write friendly definition Word List Vocabulary Acquisition DAY 3 and/or DAY 4 1. Review the word Friendly Definition Physical Representation 2. Show how the word works Synonyms/antonym Word Problems Related words/phrases Example/non-example DAY 5 1. Review the word Friendly definition Physical Representation 3. Write a sentence at least 2 rich words (1 action) correct spelling correct punctuation correct subject/predicate agreement clear and clean writing

Orientation (flipped) Notes: REFLECTION (Flip): takes an image and makes a mirror image in a plane across a given axis of reflection Reflections PRESERVE: Size Shape CHANGE: Orientation (flipped)

Storm Check (Think, Write, Discuss, Report) What is the difference between a translation and a reflection? A translation ____________________________ _______________________________________. A reflection _____________________________

ABCDE A’B’C’D’E’ (_____ , _____) (_____ , _____) (_____ , _____) The BLUE pentagon is the PRE-IMAGE and the GREEN one is the IMAGE. How would you describe the reflection? The IMAGE has reflected across ____________. ABCDE Coordinates for Point A (_____ , _____) A B Coordinates for Point A’ (_____ , _____) D E C Coordinates for Point B (_____ , _____) E’ D’ C’ Coordinates for Point B’ (_____ , _____) A’ B’ A’B’C’D’E’

ABCDE A’B’C’D’E’ (_____ , _____) (_____ , _____) (_____ , _____) The BLUE pentagon is the PRE-IMAGE and the GREEN one is the IMAGE. How would you describe the reflection? The IMAGE has reflected across ____________. ABCDE Coordinates for Point C (_____ , _____) A B Coordinates for Point C’ (_____ , _____) D E C Coordinates for Point D (_____ , _____) E’ D’ C’ Coordinates for Point D’ (_____ , _____) A’ B’ A’B’C’D’E’

Storm Check (Think, Write, Discuss, Report) What rule for changes in coordinates would you create for reflections across the x-axis? A reflection across the x-axis changes the original pre-image coordinates from (x, y) to _______________________________________. R x-axis(x, y)  (____ , ____)

(_____ , _____) (_____ , _____) (_____ , _____) (_____ , _____) The BLUE triangle is the PRE-IMAGE and the GREEN triangle is the IMAGE. How would you describe the reflection? The IMAGE has reflected across ____________. ABC A’B’C’ Coordinates for Point A (_____ , _____) A A’ Coordinates for Point A’ (_____ , _____) B B’ C C’ Coordinates for Point B (_____ , _____) Coordinates for Point B’ (_____ , _____)

Storm Check (Think, Write, Discuss, Report) What rule for changes in coordinates would you create for reflections across the y-axis? A reflection across the y-axis changes the original pre-image coordinates from (x, y) to _______________________________________. R y-axis(x, y)  (____ , ____)

Reflection Vocabulary Pre-Image Image Axis of Reflection

REFLECTION across y = x y = x (a, b)  (b, a)

REFLECTION (Flip): There are 4 main axes of reflection: x-axis (a, b)  (a, -b) y-axis (a, b)  (-a, b) y = x (a, b)  (b, a) y = -x (a, b)  (-b, -a)

Date: Title: IM1 – G-CO-4 Lesson 2 Reflections Learning Target By the end of the period, I will create a definition of reflection in 2 dimensions and apply that definition to a given object. I will demonstrate this by completing Four-Square Notes and by solving problems in a pair/group activity.

Home Work 1-2-3: 1) Class 4-Square Notes Put In Binder? 2) Section ______ 3) Section ______ TxtBk. Problems_________ Notes Copied on blank sheet Solved and Put in Binder? of paper in Binder? Table of Contents Date Description Date Due