Geometry is starting a chapter on area, at the beginning of the period I put this up.
It was fun to see students expressions as they figured out that both large triangles have the same base/height and are also made up of the same pieces. The group was able to come up with the solution after about 5 minutes.
For the rest of the period they worked on Dan’s Coffee Traveler Three-Act.
Here are some of the end results.