Lesson 3.5 day 6
Review Day
Focus: Stella’s Stunners — navigation instrument update — tiered problem bank — targeted practice across all six rows
Open the lesson with Stella’s Stunners. The problem — two crossing parallelograms, find all angles congruent to angle 1 — is short, genuinely demanding, and produces exactly the right mathematical conversations about transversal chains and justified claims.
In Year 1, students worked on this problem toward the end of the unit and something important happened: all groups wrote congruence statements with justifications even though no one asked them to. The habit was beginning to take hold. Groups that intuitively saw that separate transversals could be connected through the law of syllogism were doing advanced thinking. Groups that incorrectly assumed corresponding angles across two separate transversals generated a productive conversation about which parallel lines and which transversal justify each claim.
The Stella’s Stunners warm-up should run 15–20 minutes. After the debrief, transition to the 26-problem review bank. Students use their navigation instrument to direct their own practice: identify the row where you are weakest, work there first, then address the next weakest row. The bank is heavily weighted toward proof writing (Rows 5 and 6) because that is where the most growth still happens at this point in the unit.
Close the lesson with a final navigation instrument update. Students should be able to compare where they are now to where they were at the start of the unit. This is the last chance for self-directed practice before the assessment.