Geometry: Slices

Objectives

• Students will predict and identify the shapes of two-dimensional cross-sections that are formed when three-dimensional figures are cut by horizontal and vertical planes.
• Students will draw, construct, and describe geometrical figures and describe the relationships among them.

Vocabulary

• rectangular prism
• triangular prism
• square pyramid
• tetrahedron
• cylinder
• cone

About the Lesson

This lesson involves exploring the shapes formed from 3D figures cut by a horizontal and/or a vertical plane.
As a result, students will:

• Predict the outcomes of moving planes through 3D figures.
• Move a horizontal and vertical plane through the figure to check their predictions.
• Explain any similarities or differences they see in the shapes that are formed as the planes move through the figure.
• Determine what 3D figure was sliced. given a description of the shapes formed from slicing the figure both horizontally and vertically.