This Problem Set is a part of the Lesson 4, Unit 7, Grade 3. In this lesson, students classify a set of quadrilateral cut-outs into increasingly restrictive categories. They identify trapezoids, parallelograms, rhombuses, rectangles, squares, and quadrilaterals that do not belong to any of these categories. Finally, they decompose quadrilaterals into two triangles by drawing diagonals between opposite corners.