# Dilation Project

Introduction

Dilation leads us to similarity. As we dilate an image, does it maintain all of the properties of the pre-image? No, the pre-image can change size. However, because the change is only proportional, the image maintains all other properties of the pre-image, other than size. Thus it is a transformation that is non-isometric. If the image is proportional to the pre-image, it is SIMILAR.

Dilations

PROJECT INSTRUCTIONS AND RUBRIC

DUE: Wednesday, October 26, 2022

• You may dilate a cartoon, photograph, clip-art image or illustration.
• Your image must include curves and inner detail. (No basic polygons allowed!)
• Use construction paper, foam board, cardboard or poster board (any color).
• You will need a ruler, compass, pencil, eraser, markers, and/or colored pencils.
Process

Task: Check off each step as you complete it.

1. _______ Find an image to dilate online (Google is a great place to start). Print the image and glue or tape this image to your poster-board or paper.

1. _______ Use a pencil to draw a point to represent the center of dilation.  Label this point “D”.

1. _______ Determine your Scale Factor.  Your scale factor cannot be 1:1.

1. _______Pick a number of key points along the edge of your image and then dilate those points by your chosen scale factor.  You must have at least 20 control points. You must use a pencil and ruler for this step.

1. _______Once you have moved your control points, connect them to form the outline of your dilation image. You do not have to dilate the minor details inside of your figure.

1. _______Use a marker or colored pencil to trace your newly created dilation. Do not erase the line segments that you used in the dilation process.  It is OK to color over them, though.

1. _______Add the inner details of your pre-image to the dilation image and use color to enhance.

1. _______Give your dilation a title and neatly write it across the top of your project.

1. _______Write your name in the lower right-hand corner of your project.

1. _______In the space above your name, use measurements and computations to show what the scale factor of dilation is for your project.

Evaluation

Evaluation Rubric:

 Requirements Points Possible My Check Teacher’s Grade Pre-image is on paper. 5 Center of dilation is on paper and properly labeled. 5 At least 20 points are accurately dilated. 20 Line segments are drawn with a pencil and a ruler. 5 Outline is drawn and traced over with marker or colored pencil. 5 Inner details are added to dilation image. 10 Title is neatly displayed across the top of the project. 5 Image is accurate. 10 Color is used to enhance the display. 5 Project is neat. 5 Complexity of chosen image is apparent (no basic shapes, such as a star, a polygon, a circle, etc.) 10 Scale Factor is accurate 5 Name is printed in the lower right front corner of the poster. 5 Project is completed on time. (5 points will be deducted for every day the project is late.) 5

Total Possible:    100                                                                                                                                Project Total:________

NOTE: This paper must be turned in with your project!

Conclusion

Future Connections:

This lesson leads us into our next Similarity and Right Triangle standards, where we will delve deeper into the properties of similarity, particularly with Triangle Similarity, which will then lead to Trigonometry.

Credits