What is the true number of faces of a rectangular prism?

In this lesson you will learn how to analyze rectangular prisms by locating pairs of

congruent faces.

Let’s ReviewLet’s Review

Two figures are congruent when they are exactly the same shape and size.

congruent: not congruent:

Let’s ReviewLet’s Review

Two faces on a 3D solid are parallel when they never intersect.

parallel: not parallel:

Let’s ReviewLet’s Review

A prism is a three-dimensional figure with two parallel and congruent polygonal bases.

Let’s ReviewCore Lesson

There are three different types of rectangular prisms:

Let’s ReviewCore Lesson

Some prisms have 3 different pairs of matching, congruent faces.

Let’s ReviewCore Lesson

Let’s ReviewCore Lesson

Some prisms have 2 different sizes of congruent faces.

Let’s ReviewCore Lesson

Let’s ReviewCore Lesson

Some prisms have 1 face size.(These prisms are called cubes.)

Let’s ReviewCore Lesson

Let’s ReviewCore Lesson

Some rectangular prisms have 3 different pairs of matching, congruent faces.

Some rectangular prisms have 2 different sizes of congruent faces.

Some prisms (cubes) have 1 face size.

In this lesson you learned how to analyze rectangular prisms by locating pairs of congruent

faces.

Let’s ReviewGuided Practice

Describe the difference between the gift packages that you see, below. Draw a net for each gift.

The first gift has two face sizes. There are squares on top/bottom, and rectangles on the four sides.

This gift is a cube, so it has 6 faces that are all the same size.

Let’s ReviewExtension Activities

Below is a sample of each of the three types of rectangular prisms. Draw the net for each of these prisms, paying careful attention to the different sizes of the rectangular faces.

Let’s ReviewExtension ActivitiesLook around your classroom. Locate one of each of the different

types of rectangular prisms that you learned about, in this lesson. Use your observations to complete the chart, below. (For example: You might write “dice” as an example of a prism with 1 face size.)

When you are finished, you and a partner will describe to one another why you selected each object.

3 face sizes =

2 face sizes =

1 face size =

# face sizes: object:

Let’s ReviewQuick Quiz

How many different sizes of rectangular faces are there on a cube? Prove your answer by drawing a net.

How many different sizes of rectangular faces are there on your mattress? Prove your answer by drawing a net.