Unit 3, Lesson 1# What Lies Behind "Same Shape"?

EngageNY 45 min(s)

Students learn the definition of dilation and why "same shape" is not good enough to say when two figures are similar. Students know that dilations magnify and shrink figures. The goal of this module is to arrive at a precise understanding of the concept of similarity: What does it mean for two geometric figures to have "the same shape but not necessarily the same size?" Note that students were introduced to the concept of congruence in the last module, and they are being introduced to the concept of dilation in this module.