In this lesson, students will attend to precision (MP6) while proving all points are congruent and all segments of the same length are congruent. Justifying why points coincide in figures with congruent parts in a rigorous way requires great attention to detail. After this lesson, students can skip the steps they prove here. This allows them to start by saying a transformation exists to take a segment to a congruent segment and focus their attention on using the remaining information to prove the triangles congruent.

Math Community

Today’s activity is for students to individually reflect on the norms generated so far. During the Cool-down, students provide feedback on the norms, sharing those they agree with and those they feel need revision or removal. These suggestions will inform the next version of the classroom norms.