Mrs. Steinfeld’s geometry class worked on a fun, hands-on activity to prove the triangle inequality theorem, the Pythagorean theorem, and the Pythagorean theorem converse. Students worked together in groups to construct four triangles: one that had three sides that wouldn’t close, a right triangle, an acute triangle and an obtuse triangle. The girls thought about and measured pairs of sides that would work to create these four triangles, and proved their side measurements to be correct by showing that the angle measurements also lined up. It was a fun and creative project that allowed the students to practice using the theorems they learned in class.