In this lesson, students apply the triangle congruence theorems to parallelograms in order to generate and prove congruence theorems for parallelograms. Students have an opportunity to make sense of problems and persevere in solving them (MP1) as they take the general question “When are parallelograms congruent?” and figure out how to generate cases to test. As students continue to test the cases rigorously and then prove their conjectures, they are expressing regularity in repeated reasoning (MP8). 

Technology isn't required for this lesson, but there are opportunities for students to choose to use appropriate technology to solve problems. We recommend making technology available.

Math Community

In today’s activities, students are introduced to the idea of math norms as expectations that help everyone in the room feel safe, comfortable, and productive doing math together. Students then consider what norms would connect and support the math actions the class recorded so far in the Math Community Chart.