In this lesson, students review the definition of scale factor by comparing examples and non-examples of a scaled image. Then students define dilation as a transformation with a center and a positive scale factor that takes a point along the ray to another point that is a distance times farther away from than is. Then students practice dilating points on a figure to better understand the concept.

When students are drawing a dilation they must both measure precisely and pay attention to which of the labeled points is being used as the center (MP6).