Lesson objective: Identify three dimensional figures by their two dimensional nets and then use nets to distinguish between prisms and pyramids.

Students bring prior knowledge of classifying two-dimensional shapes from CCSS 5.G.B3 and B.4. This prior knowledge is extended to geometric nets as students use them to classify three dimensional figures. A conceptual challenge students may encounter is visualizing the two-dimensional net of a three-dimensional figure or the three-dimensional figure from the two-dimensional net.

The concept is developed through work with nets of prisms and pyramids, which students will sort based on their attributes, helping to identify key characteristics of the two types of figures.

This work helps students deepen their understanding of number because two dimensional nets require different measurements and labels than three dimensional figures even though they may represent the same exact figure.

Students engage in Mathematical Practice 4 (Model with Mathematics) as they use nets of pyramids and prisms to make connections between two dimensional shapes and three dimensional figures.

Students also engage in Mathematical Practice 7 (Look for and Make Use of Structure) as they use nets to understand the properties of pyramids and prisms.

**Key vocabulary:**

- base
- congruent
- cube
- face
- hexagonal prism
- hexagonal pyramid
- net
- polygon
- pentagonal prism
- pentagonal pyramid
- prism
- pyramid
- rectangular prism
- square pyramid
- three dimensional figure
- triangular prism
- triangular pyramid
- two dimensional shape

**Special materials needed:**

- optional: handout of nets, copied onto card stock (1 per student, pair, or team)