"What's a Quadrilateral?"

BOPDs talked about the word, "quadrilateral" and based on their shared definition, they came up with one for the class. Then every student had to draw three examples and three non-examples of quadrilaterals. We placed these drawings in a pile and broke the class into two groups. Each group played the game,"What's a quadrilateral?". Students take turns picking from the pile and reasoning with the shapes and attributes to prove whether or not the drawing is a quadrilateral. There were two options aside from reasoning independently. They could use a 'lifeline', meaning they could get one more drawing from the pile and use it to compare with the first one. The comparison is aimed to help their reasoning. Another option was to 'call a friend' and ask that person to give the attributes of quadrilaterals. It was a fun game and one that got us thinking about other terms to describe shapes.