Lesson objective: Understand that shapes in different categories (rhombuses, rectangles, etc.) may share attributes.

Students bring prior knowledge of attributes of shapes from 2.G.A. This prior knowledge is extended to understanding that shapes my share attributes with more than one group. Students will examine shapes for like attributes and different attributes. A conceptual challenge students may encounter is shapes may have more than one category.

The concept is developed through work with quadrilaterals, which illustrate shapes in multiple categories.

This work helps students deepen their understanding of equivalence because shapes can be identified and categorized by their attributes.

Students engage in Mathematical Practice 7 (Look for and make use of structure) as they examine various shapes for similarities and differences.

**Key vocabulary:**

- attribute
- rectangle
- rhombus
- square
- trapezoid