Title: |
Grade 8 Mathematics Module 2, Topic C: Congruence and Angle Relationships |
URL: |
https://www.engageny.org/resource/grade-8-mathematics-module-2-topic-c-overview |
Content Source: |
EngageNY
|
Type: |
Lesson/Unit Plan
|
Overview: |
In Module 2, Topic C, on the definition and properties of congruence, students learn that congruence is just a sequence of basic rigid motions. The fundamental properties shared by all the basic rigid motions are then inherited by congruence: congruence moves lines to lines and angles to angles, and it is both distance- and degree-preserving (Lesson 11). In Grade 7, students used facts about supplementary, complementary, vertical, and adjacent angles to find the measures of unknown angles (7.G.5). This module extends that knowledge to angle relationships that are formed when two parallel lines are cut by a transversal. In Topic C, on angle relationships related to parallel lines, students learn that pairs of angles are congruent because they are angles that have been translated along a transversal, rotated around a point, or reflected across a line. Students use this knowledge of angle relationships in Lessons 13 and 14 to show why a triangle has a sum of interior angles equal to 180˚ and why the exterior angles of a triangle are the sum of the two remote interior angles of the triangle. |
Content Standard(s): |
Mathematics MA2015 (2016) Grade: 8 | 17 ) Understand that a two-dimensional figure is congruent to another if the second can be obtained from the first by a sequence of rotations, reflections, and translations; given two congruent figures, describe a sequence that exhibits the congruence between them. [8-G2]
NAEP Framework
Alabama Alternate Achievement Standards
| Mathematics MA2019 (2019) Grade: 8 | 25. Analyze and apply properties of parallel lines cut by a transversal to determine missing angle measures.
a. Use informal arguments to establish that the sum of the interior angles of a triangle is 180 degrees. Unpacked Content
Alabama Alternate Achievement Standards
|
|
|
Tags:
|
angle, congruent, exterior angle, figure, parallel lines, sum, transversal, triangles, twodimensional |
License Type:
|
Custom Permission Type See Terms: https://www.engageny.org/terms-of-use For full descriptions of license types and a guide to usage, visit :
https://creativecommons.org/licenses
|
Accessibility | Text Resources: Content is organized under headings and subheadings |
Comments | There are four lessons in this topic.
This resource is free for teachers to access and use. All resources required for the lessons are available to print from the site. |