1. Chapter 9: Transformations
9.5
Dilations

2. Dilations
transformation whose preimage and image are similar (not same size)
not an isometry!
every dilation has a center and a scale factor

3. Dilations enlargement: reduction: scale factor > 1
scale factor between 0 and 1

4. Example 1
The blue triangle is a dilation image of the red triangle. Describe the dilation.

5. Example 1a
The blue quadrilateral is a dilation image of the red quadrilateral. Describe the dilation.

6. Example 2
The packaging lists a model car’s length as 7.6 cm. It also gives the scale as 1:63. What is the length of the actual car?

7. Example 2a
The height of a tractor-trailer truck is 4.2 m. The scale factor for a model of the truck is 1/54. Find the height of the model to the nearest centimeter.

8. Example 3
ΔPZG has vertices P(2,0), Z(-1,1/2), and G(1,-2). What are the coordinates of the image of P for a dilation with center (0,0) and scale factor 3?

9. Example 3a
ΔPZG has vertices P(2,0), Z(-1,1/2), and G(1,-2). What are the coordinates of the image of P for a dilation with center (0,0) and scale factor 1/2 .

10. Homework
p. 500
2-24 even
**might want graph paper!**