2. Chapter 2 Similarity and Dilations
Lesson 3 dilations

3. Dilations Desmos Dilation Activity Students go to student.desmos.com
Type in the code your teacher gives you

4. Dilations I can determine coordinates after a dilation.
I can compare and contrast a figure and its dilation.
I can determine the scale factor of a dilation.

6. Chapter 2 Similarity and Dilations
Lesson 3 dilations

7. Vocabulary
(x, y) (kx, ky)

8. Dilations

9. Example 1 – C(1, 4), A(2, 2), T(5, 5); k = 2
Graph the original figure.
Determine the coordinates of the image.
Give the algebraic representation.
Graph the dilation.

10. Example 2 – Compare and contrast the pair of figures.
C(1, 4), A(2, 2), T(5, 5); k = 2

11. Try This
R(1, 1), S(1, 7), T(5, 7), U(5, 1); k = 3 4

12. Example 3 – Determine the scale factor.
Lucas wants to enlarge a 3- by 5-inch photo to a 7 ½ - by 12 ½ -inch photo. What is the scale factor of the dilation?

13. Try This
A graphic designer created a logo on 8½ by 11-inch paper. In order to be placed on a business card, the logo needs to be inches by inches. What is the scale factor of the dilation?

14. Dilations I can determine coordinates after a dilation.
I can compare and contrast a figure and its dilation.
I can determine the scale factor of a dilation.

15. `
If the scale factor of a dilation is 3 2 , is the dilation an enlargement or a reduction? Explain.

17. Chapter 2 Similarity and Dilations
Lesson 3 dilations

18. Dilations
Draw a set of axes. Graph given points, connecting in order. Also, make a table of your points.
Select (draw) a scale factor. Record your scale factor on your paper.
Dilate your shape by the scale factor. Graph it and make a table of your dilated points.
Write the algebraic expression for your dilation and write a verbal description of your dilation.

19. Dilations
A dilation is a transformation, or mapping, that enlarges or reduces a figure by a scale factor relative to a center point. A dilation with a scale factor of k will be:
an enlargement if k > 1,
a reduction if 0 < k < 1,
the same as the original figure if k = 1.