Intro to congruence and transformations always make sense when I do this activity. Who's congruent? Students physically move their shapes, transforming them, showing congruence. Super quick, super effective. Then we have a race to see who can get tangrams put together first.
BTW, rough day yesterday with one precal class that really didn't get the grading activity, and really isn't taking anything seriously. Had to have a talk with them. Never know if that's worth it... fourth week of school and kids not following the 3-4 simple rules I have is bumming me out, frustrating me, making me meaner than I need to be... Management is so much more of a challenge in a new school with kids I don't know, and who don't know me! #spoiledby5yearsteachingthesamekids