Fishtank Learning

6th Grade Math
Unit 7: Geometry
Lesson 14

Objective

Describe features of and identify nets that match prisms and pyramids.

Anchor Problems - Problem 1

A set of prisms and a set of pyramids are shown below.

Prisms and pyramids illustrated, including triangular, square, and hexagonal bases.

a. Compare and contrast the features you notice about prisms and pyramids. In particular, identify and compare the faces, edges, and vertices.

b. Identify the base of each figure and name each figure.

c. Describe how a pentagonal prism and a pentagonal pyramid are similar and different.

Guiding Questions

Define a face of a three-dimensional polyhedron. What faces do you see in each prism? Do you notice a pattern? What faces do you see in each pyramid? Do you notice a pattern?
Define edge and vertex and identify them in the prisms and pyramids.
Define base and identify the base in each figure.
How many pentagon faces does a pentagonal pyramid have? A pentagonal prism?
What are the other faces on a pentagonal pyramid? On a pentagonal prism?

Notes

Use this Anchor Problem to introduce students to polyhedra, closed three-dimensional spaces with polygons for faces. Define and identify face, vertex, edge, and base in the various prisms and pyramids.
Prior to sixth grade, students will mainly have experience with rectangular prisms and pyramids may be new to them. Students should observe that prisms have two of the same shape for the base that are connected to each other by rectangles, and pyramids have one base from which triangles extend and meet at a common vertex. These features will help students in making connections between the three-dimensional representations and the two-dimensional nets.
A Venn diagram or other organizational chart is a good tool to use for this problem. If 3D shapes are available, allow students to explore the physical objects as well, especially comparing prisms and pyramids with the same base (MP.5).

Anchor Problems - Problem 2

Your teacher will demonstrate the flattening and folding of a prism and a pyramid using a net. Observe how a prism and pyramid can be flattened into a two-dimensional form called a net. Observe how a two-dimensional net can be folded up to re-form the three-dimensional polyhedron. Think about the shapes and features of the net that connect back to the three-dimensional figure.

Then, explore with your own nets using the nets provided in Nets. For each net, answer the following questions:

a. Do you think this net will fold into a prism, a pyramid, or neither? Why or why not?

b. If so, what is the name of the shape?

c. Test out your answers by folding the net into a three-dimensional figure.

Guiding Questions

Describe in your own words what a net is and how it is related to a three-dimensional polyhedron.
What do you notice about the edges and vertices of the figure as it is folded and unfolded?
Do the faces of the figure change as it is folded and unfolded?
What features define a prism? What features define a pyramid? Where can you see these in the net?
Do you think there is only one net per three-dimensional figure? Why or why not?
Challenge: How many different nets for a cube can you find?

Notes

For this Anchor Problem, choose a prism and a pyramid from the template Nets and cut them out to use in your demonstration. For student exploration, provide a template to each student (or pair or small group) and have them cut out the nets (or pre-cut before the lesson). (MP.5)
As students discuss part (a), listen for appropriate use of new vocabulary in students’ explanations. Share examples with the whole class.

Anchor Problems - Problem 3

Match each net below to its corresponding three-dimensional figure. Name each three-dimensional figure.

Net diagrams for identifying 3D shapes: pyramid, rectangular prism, triangular prism, cube, and rectangular prism. Net of a cube, rectangular prism, triangular pyramid, triangular prism, and triangular prism with a triangular base.

Guiding Questions

What features are you looking for in the net and in the three-dimensional figure to know if they match?
Which nets represent prisms? Which nets represent pyramids? How do you know?
How are figures C and D similar? How are they different?
How are figures C and E similar? How are they different?
How are figures E and B similar? How are they different?

Notes

Before jumping into the matching activity, have students spend time observing the shapes and features of the nets and polyhedra first (MP.7).

Problem Set

View Problem Set

Target Task

Determine if each claim is accurate. Explain why or why not.

a. Claim: This net will fold into a square prism.

Net of a square prism with 6 faces, 4 faces shaded.

b. Claim: This net will fold into a pentagonal pyramid.

Net of a pentagonal pyramid with five triangular faces and a pentagonal base.

Fishtank Learning

6th Grade MathUnit 7: GeometryLesson 14

Objective

Anchor Problems - Problem 1

Anchor Problems - Problem 2

Anchor Problems - Problem 3

Problem Set

Target Task

6th Grade Math
Unit 7: Geometry
Lesson 14