Lesson 1

The purpose of this lesson is for students to recognize and name shapes based on the number of sides and vertices (corners). Students name triangles, quadrilaterals, pentagons, and hexagons.

In previous grades, students identified, described, and compared two-dimensional and three-dimensional shapes. Students learned that shapes have defining attributes and drew shapes that possessed these attributes.

In this lesson, students learn that they can identify a shape by the number of sides and corners it has. Students sort shapes into examples and non-examples of triangles, quadrilaterals, pentagons, and hexagons. They define triangle, quadrilateral, pentagon, and hexagon based on the number of sides and corners and use these terms to name shapes. Throughout the lesson, students have opportunities to think about how to clearly describe the attributes of shapes to others and consider the precision of their language (MP6). It is not necessary for students to use the term vertices, so they are referred to as “corners” in this unit.

• Create a set of cards from the blackline master for each group of 2.
• Remove the shape name cards for this activity. Students will use them in the next activity.

• Each group of 2 needs the set of cards from the previous activity, including the shape name cards.

• Each group of 2 needs a set of cards from the previous activity.

In grade 1, students learned to distinguish between attributes that define a shape and those that do not. How does this understanding help students classify shapes as quadrilaterals, pentagons, and hexagons?