Unit 2, Lesson 3
Dilations with No Grid
Grade 8
Preparation
Lesson Narrative
In this lesson, students apply dilations to points with no grid. In order to perform a dilation, three pieces of information are needed: a center of dilation, a scale factor, and a point to be dilated.
Students begin by dilating points along a ray in preparation to perform dilations of points and polygons without a grid. They must select and use appropriate tools as they identify centers of dilation, scale factors, and images of dilation, and use dilations to make perspective drawings (MP5).
- Create a dilation of a figure given a scale factor and center of dilation.
- Explain (orally) the effect of the scale factor on the size of the image of a polygon and its distance from the center of dilation.
- Identify the center, scale factor, and image of a dilation without a circular grid.
Let’s dilate figures not on grids.
Required Preparation
Provide access to geometry toolkits.
Provide access to geometry toolkits.
Provide access to geometry toolkits.