Lesson Plan

Define a dilation in terms of a center point and a scale factor

Verify experimentally that a dilation takes a line not passing through the center to a parallel line

Verify experimentally that a dilation leaves a line passing through the center unchanged

Verify experimentally that the dilation of a line segment is longer or shorter in the ratio given by the scale factor

Perform dilations on geometric figures using graph paper, tracing paper, or geometry software

Distinguish dilations from rigid motions by recognizing that dilations change size but preserve shape

HSG.SRT.A.1

HSG.SRT.A.1: Verify experimentally the properties of dilations given by a center and a scale factor: a. A dilation takes a line not passing through the center of the dilation to a parallel line, and leaves a line passing through the center unchanged. b. The dilation of a line segment is longer or shorter in the ratio given by the scale factor.