# ALEX Resources

Narrow Results:
 Lesson Plans (1) Classroom Resources (2)

ALEX Lesson Plans
Subject: Mathematics (9 - 12)
Title: Triangle Congruence with Rigid Motions
Description:

This lesson will provide instruction on proving triangles to be congruent using rigid motions. Using the concept of transformations, the students will be able to manipulate the triangle on the coordinate plane. When using the coordinate plane to test congruence, the triangle or other object will slide, rotate, or flip to map onto the other object. Sometimes, the student will use a combination of the transformations.

This lesson results from the ALEX Resource Gap Project.

ALEX Classroom Resources
Subject: Mathematics (9 - 12), Mathematics (9 - 12)
Title: Geometry Module 1, Topic D: Congruence
URL: https://www.engageny.org/resource/geometry-module-1-topic-d-overview
Description:

In Module 1, Topic D, students use the knowledge of rigid motions developed in Topic C to determine and prove triangle congruence. At this point, students have a well-developed definition of congruence supported by empirical investigation. They can now develop an understanding of traditional congruence criteria for triangles, such as SAS, ASA, and SSS, and devise formal methods of proof by direct use of transformations. As students prove congruence using the three criteria, they investigate why AAS also leads toward a viable proof of congruence and why they cannot use SSA to establish congruence. Examining and establishing these methods of proving congruency leads to analysis and application of specific properties of lines, angles, and polygons in Topic E.

Subject: Mathematics (9 - 12), Mathematics (9 - 12)
Title: Geometry Module 1, Topic G: Axiomatic Systems
URL: https://www.engageny.org/resource/geometry-module-1-topic-g-overview
Description:

In Module 1, Topic G, students review material covered throughout the module. Additionally, students discuss the structure of geometry as an axiomatic system.

ALEX Classroom Resources: 2