Similarity and Dilation (HS)

Grade Level High School, Middle School
Location United States
Time Period
Topic Math and Maps


A map is a proportional, shrunken down version of an actual location. By connecting the mathematical ideas of similarity and dilation to maps, students see the mathematics in action in the real world.
In this lesson, the concept of similarity is expanded to dilation, the idea of shrinking and enlarging a shape as a transformation on the coordinate plane. Students review the properties of similarity and apply them to investigate maps of the same place but at different scales. From there, students apply the definition of dilation to experiment with similarity – this time, looking at the change in coordinates rather than the change in side lengths.

Norman B. Leventhal Map Center (