Lesson 6

3-D Shapes

Est. Class Sessions: 2

Developing the Lesson

Part 2. Using Properties of Shapes

Describing 3-D Shapes. Introduce the mystery box and explain that it has a variety of three-dimensional shapes inside it. See Materials Preparation.

Begin the activity by saying:

X
  • I put some 3-D shapes into a mystery box and i pulled one shape out of the box. How can we describe this shape? (Possible responses may include number of corners, faces, edges; whether there are curved or flat surfaces; shapes of faces; whether they can roll or be stacked.)

If students use descriptions based on the color, size, and material of the 3-D object, ask:

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  • Does this description fit all cubes? (Possible responses: No, here is another box that is a cube and it isn't made out of paper and it's not blue.)

Repeat this discussion with other shapes.

Direct student pairs to select a shape from the mystery box. Students work with a partner to identify and describe their three-dimensional shape in as many ways as they can on a self-adhesive note. Allow students to use their own words in their descriptions.

After students have worked on the descriptions, have one student from each pair add the self-adhesive notes with their descriptions of the three-dimensional shape on the Properties of 3-D Shapes chart. See Materials Preparation.

As each group member adds their self-adhesive note to the chart, have them read their descriptions to the class and ask:

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  • Does anyone have any descriptions to add for this shape? (Possible responses include: It has parallel sides. It has a point on the top. It has square corners.)
  • Are there any changes you would make to the chart? (Students may want to change any descriptions that do not fit the 3-dimensional shape.)
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Display the Properties of 3-D Shapes chart so that students can refer to it throughout the remainder of this unit. Do not expect students to memorize geometric terms or properties of each 3-D shape.

Play Guess My Shape. Introduce the activity Guess My Shape. Give clues about a three-dimensional shape and ask students to guess which shape you are describing.

Ask:

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  • I am thinking of a 3-D shape that has 6 squares. All the corners are square corners. It does not roll, and you can stack several of them on top of each other. What shape am I? (cube)

After several examples, give students an opportunity to provide clues to the class. Students may refer to the Properties of 3-D Shapes chart.

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Use the Guess My Shape activity to assess students' abilities to describe 3-D shapes. Since this lesson helps students lay a foundation for future lessons on 3-D shapes, allow students to use everyday language to describe their shapes [E2].

Student Guide:
Student Activity Book:
Master: