Unit 1, Lesson 11
Polyhedra and Nets
Accelerated 6
Preparation
Lesson Narrative
In this lesson, students learn about polyhedra and their nets. They also study prisms and pyramids as types of polyhedra with certain defining features.
Students begin by identifying the defining characteristics of polyhedra. They learn or review terminology, such as "faces," "edges," and "vertices," as they develop a working definition of "polyhedra."
Next, students explore the defining characteristics of prisms and pyramids. They consider the polygons that constitute the faces of a given prism or pyramid and how to arrange them into nets that can be assembled into the given polyhedron.
Then they work in groups to assemble two prisms and a pyramid from given nets and use nets to find the surface area of each polyhedron. To support students in reasoning about area, the nets are presented with a grid.
As students calculate surface area and consider how to account for all the faces of a polyhedron, they have opportunities to look for and make use of structure, in both the arrangement and measurements of the polygons that compose the polyhedron (MP7).
- Comprehend and use the words “face”, “edge”, “vertex”, and “base” to describe polyhedra (in spoken and written language).
- Match polyhedra with their nets and justify (orally) that they match.
- Use a net with gridlines to calculate the surface area of a prism or pyramid and explain (in writing) the solution method.
Let's use nets to find the surface area of polyhedra.
Required Materials
Activity 2
Required Preparation
Assemble collections of geometric figures that each contains at least 2 familiar polyhedra, 2 unfamiliar polyhedra, and 2 non-polyhedra. Prepare one collection for each group of 3–4 students. If pre-made polyhedra are unavailable, assemble some from the nets in the blackline master.
Print and pre-cut the nets and polygons in the blackline master. Prepare 1 set per group of 3–4 students, along with tape to join the polygons into a net.
Make copies of the nets in the blackline master. Prepare one set of 3 nets (A, B, and C) and provide some glue or tape for each group of 3 students.
A base is a specific face of a prism or pyramid.
A prism has 2 identical bases that are parallel. A pyramid has 1 base.
A prism or pyramid is named for the shape of its base.
A net is a two-dimensional figure that can be folded to make a three-dimensional figure.
Here is a net for a cube.