Illuminations: Geometric Solids and Their Properties

Geometric Solids and Their Properties

Unit Overview

Lesson 1

Lesson 2

Lesson 3

Lesson 4

Lesson 5

Construct a Solid

Students construct physical models of geometric solids.

Learning Objectives

Students will

analyze characteristics and properties of three dimensional geometric shapes
construct physical models of geometric solids

Materials

Geometric Solids Tool
Construction tools, such as coffee stirrers, twist ties, straws, pipe cleaners, toothpicks, gumdrops, etc.

Instructional Plan

For this lesson, students will need to work with a partner and construct one or more of the geometric solids out of coffee stirrers and twist ties, straws and pipe cleaners, toothpicks and gumdrops, or other available supplies. For example, a tetrahedron built out of straws is shown:

Students should use the Geometric Solids Tool to help them build the physical model.

Geometric Solids Tool

Each pair of students should record how you constructed each solid in a table, such as the one below.

This is a meaningful activity for students. You may wish to start with simple polyhedra, such as a cube or a tetrahedron. Students can rotate their solid, count the faces, corners, and edges and compare their results with the ones in the table.

Shape

How did you construct the shape?

Tetrahedron

Cube

Octahedron

Dodecahedron

Icosahedron

Irregular Polyhedron

Draw attention to the fact that these constructions look like the transparent shapes in the computer program. They may wish to look at their shape on the computer, using the transparent tool.

Early finishers can build shapes of their own. As in the previous part of the lesson, they should record the shape and information about the shape in their tables.

Remind students that their constructions are only representations of the geometric solids. Students should note the lack of actual "faces" in their representations, since they are simply open-air spaces.

NCTM Standards and Expectations

Geometry 3-5

Investigate, describe, and reason about the results of subdividing, combining, and transforming shapes.
Build and draw geometric objects.

Applet generously provided by L. O. Cannon, James Dorward, E. Robert Heal, and Richard Wellman (Utah State University, www.matti.usu.edu). The USU MATTI project is supported by the National Science Foundation (award number 9819107). Copyright 1999.