Begin the lesson by asking students if they are familiar with shape jackets. Based upon their experiences in this unit, they should be able to identify what a shape jacket is.
Pose the following questions to students.
Look at these two jackets. Which solids do you think they match?
| Jacket number 1 |
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Jacket number 2 |
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The above images are available on the Shape Jackets overhead.
Students should recognize that both jackets form triangular pyramids.
Next, introduce the formal geometry terms. A jacket for a geometric solid that can be folded to create the surface of the solid is called a net. A net is a way of representing a polyhedron in two dimensions. (A net is a two-dimensional figure with indicated lines for folding that folds into a three-dimensional polyhedron.)
For this part of the activity, students should work with a partner. Look at the cube. Ask students to plan how they will make a net for a cube.
Students can use grid paper to make their nets. They should fold their nets to create a cube, making sure that an actual cube is formed.
Students should make nets for other solids, such as rectangular prisms, triangular prisms, and square pyramids.
