**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.
**Standard(s): **

[MA2015] GEO (9-12) 8: Explain how the criteria for triangle congruence, angle-side-angle (ASA), side-angle-side (SAS), and side-side-side (SSS), follow from the definition of congruence in terms of rigid motions. [G-CO8]

**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.