In a traditional Montessori classroom, the Geometric Charts (including the Triangle Charts) are used as a supplement to the geometry materials. They demonstrate the geometric principles of congruence, similarity and equivalence, and are also used to represent fractional equivalence. The charts can also be used to explore area. These charts can be used as a stand alone tool for working with these concepts, but have more value when used in conjunction with moveable triangle pieces (included) or tr