Candice and Trevor have gotten a job working at the mall for the holiday season. They are both going to be working in the wrapping station. During the holidays, the mall offers free gift wrapping. People can come through and have their gifts wrapped. If they want to make a donation they can and that money is used to help needy families.

Candice and Trevor both show up on their first day for training. Mrs. Scott, the manager of the wrapping station shows them both where they will be working.

“First, we need to show you some great techniques for wrapping presents,” Mrs. Scott explains. “There are some ways that are more effective and useful than others.”

Candice and Trevor both take a seat in front of a bunch of different items.

There is a round bottle of perfume, a shoe box, a soccer ball and a magician’s hat with a round bottom and a point at the top.

“What kinds of shapes to do you see here?” Mrs. Scott asked the two.

**Before seeing Candice and Trevor’s answers, think about this question yourself. Based on the descriptions, how would you classify these objects? Make a few notes in your notebook.**

**In this Concept, you will learn how to classify three-dimensional solids. By the end of this Concept, you will know how Candice and Trevor can classify each item.**

### Guidance

In our earlier Concepts, all of the figures that we have been working with have been ** plane figures** which are

**two-dimensional figures**. This means that they have only length and width. Even a circle which has a circumference and a diameter is still a plane figure. It does not have depth.

This lesson will focus on ** solid figures** and solid figures are

**three-dimensional figures**.

**How is a solid figure different from a plane figure?**

**A** *solid figure***has length, width and height,** whereas a plane figure only has length and width.

Let’s look at some plane figures.

Now let’s look at some solid figures.

We see solid figures around us every day. Take a look around you. What solids do you see? How many faces or edges do they have? Recognizing and understanding these figures is an important key to doing geometry.

**How can we identify different solid figures?**

We can identify them according to the features that are unique to each type of solid.

### Vocabulary

Here are the vocabulary words that are found in this Concept.

- Plane figure
- a two-dimensional figure

- Solid figure
- a three-dimensional figure

- Face
- the flat polygon of a solid figure. A figure can have more than one face.

- Prism
- a three-dimensional figure with two parallel congruent polygons as bases

- Pyramid
- a three-dimensional figure with one polygon for a base and all faces meet at one vertex.