In this activity, students will dilate polygons and find the perimeter and area of both the pre-image and image. Then they find the ratios of the perimeters and areas. When they change the scale factor, all of these values automatically update and students can see that the ratio of the perimeters equals the scale factor and the ratio of the areas equals the square of the scale factor. Students will see that this is true for both enlargements and reductions.

Download the attached PDF and look over the information on the first page. Download and distribute the attached .tns file and Student Worksheet for use during the activity. A .tns file containing expected student results is also available for download.

Discuss the material from the activity pages and worksheet with students as needed.

Encourage students to summarize what they have learned from completing the activity. If desired, discuss the extension with students.