The purpose of this activity is to deepen students’ understanding that a shape can belong to multiple categories because of its attributes. Students analyze shapes and determine all the ways that each one could be named. The names may refer to a broad category such as triangle or quadrilateral, or a narrower subcategory such as rhombus or rectangle. As students name the different categories, they need to be precise about the meaning of the categories and verify the properties of the different shapes (MP6).

• “How did you describe the shape?”
• “Are there any other names that could be used to describe the shape?”

• Select 1–2 students to share the terms they selected for each of the last four quadrilaterals and their reasoning.
• Consider asking:
  • “Who can restate _____’s reasoning in a different way?”
  • “Does anyone want to add on to _____’s reasoning?”
  • “Do you agree or disagree? Why?”
• “The last shape can be described with 4 of the choices. How is it possible that it can be described in so many ways?” (It is a quadrilateral because it has 4 sides. It is a rhombus because it’s a quadrilateral with 4 sides that are the same length. It is a rectangle because it has 4 right angles and 2 pairs of sides that are the same length. It is a square because it has 4 sides that are the same length and 4 right angles. The last three are more specific descriptions of a quadrilateral.)

The purpose of this activity is for students to apply what they know about the defining attributes of rectangles, rhombuses, and squares to draw shapes that are not those quadrilaterals. They use geometric attributes to explain why their drawings meet the criteria.

• Select students to share their drawings and explanations for the first three problems.
• Highlight explanations that include the defining attributes of squares, rectangles, and rhombuses.
• Invite students to share as many different quadrilaterals as they can think of for the last problem. Display as many as possible.