Unit 5, Lesson 3
Creating Cross-Sections by Dilating
Geometry
Preparation
Lesson Narrative
In this lesson, students create dilations of a rectangle and suspend them to resemble cross-sections of a pyramid. They learn that given a pyramid’s base, its cross-sections are dilations of the base, with scale factors between 0 and 1.
Through articulating things they notice and things they wonder about dilations, students attend to precision in the language they use to describe what they see (MP6).
- Comprehend that a pyramid’s cross-sections can be thought of as dilations of its base, using scale factors from 0 to 1.
- Let’s create cross-sections by doing dilations.