Reviewing Two Dimensional Shapes

The children used problem solving and cooperative learning in order to create and present the five 2-D shapes we have studied. After planning who would make each shape, the groups set out to attempt to make a circle, square, rectangle, triangle, and hexagon with these materials: mini-marshmallows, toothpicks, and craft sticks. As they worked they found out revisions had to be made. Finally, the groups presented their creations to the class and justified that the shape was in fact a triangle because it had 3 vertices and 3 sides. The difficult shapes were the rectangle and the circle. A few groups figured out how to make them using the materials provided and also gave valid reasons for their choices (the circle had to be made with the marshmallows because circles have curved lines; the rectangle had to be made with 2 craft sticks for the long sides and 2 toothpicks for the short sides).