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Grade 8 Mathematics Module 2, Topic A: Definitions and Properties of the Basic Rigid Motions

  Classroom Resource Information  

Title:

 Grade 8 Mathematics Module 2, Topic A: Definitions and Properties of the Basic Rigid Motions

URL:

 https://www.engageny.org/resource/grade-8-mathematics-module-2-topic-overview

Content Source:

 EngageNY
Type: Lesson/Unit Plan

Overview:

Throughout Module 2, Topic A, on the definitions and properties of the basic rigid motions, students verify experimentally their basic properties and, when feasible, deepen their understanding of these properties using reasoning. In particular, what students learned in Grade 4 about angles and angle measurement (4.MD.5) will be put to good use here: they learn that the basic rigid motions preserve angle measurements, as well as segment lengths.

Content Standard(s):
Mathematics
MA2019 (2019)
Grade: 8
22. Verify experimentally the properties of rigid motions (rotations, reflections, and translations): lines are taken to lines, and line segments are taken to line segments of the same length; angles are taken to angles of the same measure; and parallel lines are taken to parallel lines.

a. Given a pair of two-dimensional figures, determine if a series of rigid motions maps one figure onto the other, recognizing that if such a sequence exists the figures are congruent; describe the transformation sequence that verifies a congruence relationship.
Unpacked Content
Evidence Of Student Attainment:
Students:
  • Confirm characteristics of the figures. such as lengths of line segments, angle measures, and parallel lines as they develop a definition for congruent figures.
  • Use mathematical vocabulary to distinguish between a pair of congruent figures, noting that the figure prior to the transformation is called the preimage and the post-transformation figure is called the image.
  • Examine two figures to identify the rigid transformation(s) that produced the image from the pre-image. they can recognize the symbol for congruency (≅) and write statements of congruence.
Teacher Vocabulary:
  • Congruent
  • Rotation
  • Reflection
  • Translation
Knowledge:
Students know:
  • How to measure line segments and angles.
  • That similar figures have congruent angles.
  • The definition/concept of what a figure does when it undergoes a rotation, reflection, and translation.
  • How to perform a translation, reflection, and rotation.
Skills:
Students are able to:
  • verify by measuring and comparing lengths of a figure and its image that after a figure has been translated, reflected, or rotated its corresponding lines and line segments remain the same length.
Understanding:
Students understand that:
  • congruent figures have the same shape and size.
  • Two figures in the plane are said to be congruent if there is a sequence of rigid motions that takes one figure onto the other.
Diverse Learning Needs:
Essential Skills:
Learning Objectives:
M.8.22.1: Define rotation, reflection, and translation.
M.8.22.2: Recognize translations (slides), rotations (turns), and reflections (flips).
M.8.22.3: Distinguish between lines and line segments.
M.8.22.4: Demonstrate how to measure length.
M.8.22.5: Demonstrate how to use a protractor to measure angles.
M.8.22.6: Identify parallel lines.
M.8.22.7: Define congruent and sequence.
M.8.22.8: Compare translations to reflections.
M.8.22.9: Compare reflections to rotations.
M.8.22.10: Compare rotations to translations.
M.8.22.11: Identify attributes of two-dimensional figures.
M.8.22.12: Identify congruent figures.

Prior Knowledge Skills:
  • Define ordered pairs.
  • Name the pairs of integers and/or rational numbers of a point on a coordinate plane.
  • Demonstrate when two ordered pairs differ only by signs, the locations of the points are related by reflections across one or both axes.
  • Identify which signs indicate the location of a point in a coordinate plane.
  • Recall how to plot ordered pairs on a coordinate plane.
  • Define reflections.
  • Define reflections.
  • Calculate the distances between points having the same first or second coordinate using absolute value.
Alabama Alternate Achievement Standards
AAS Standard:
M.AAS.8.22 Identify 3 different transformations (e.g., reflection, rotation, translation).
Tags: angle, length, lines, measurement, properties, rigid motions, segment
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Comments

There are six lessons in this topic.

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  This resource provided by:  
Author: Hannah Bradley
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