Unit 3
Similarity
Unit Narrative
In this unit, students explore similar figures as pairs of figures for which one can be taken onto the other through a sequence of rigid transformations and a dilation. The work of this unit expands upon students’ understanding of similarity, previously encountered in grade 8, and their work in an earlier unit on congruence.
The unit begins with an exploration of dilation properties, including the idea that angles are preserved through dilation and lines are taken to themselves or parallel lines depending on the center of dilation. Then students practice...