1. Today’s Lesson: What: Dilations Why: To perform dilations of figures on the coordinate plane. What: Dilations Why: To perform dilations of figures on the coordinate plane.

2. Dilations A dilation is a transformation that changes the size but not the shape of an object or figure. Every dilation has a fixed point that is called the center of dilation.

3. Remember, a dilation is any ____________________________. The scale factor controls how large or ________________ the figure will become. We dilate according to the ______________________. More specifically, we ________________ EVERY coordinate by the scale factor. What is it?? re-sizing small scale factor multiply

4. Dilations To dilate an object: 1) Graph object if necessary. 2) Multiply the coordinates of the object by the scale factor. 3) Graph new coordinates.

5. Original Coordinates: A (-2, 4)B (2, 4)C (2, 1) Dilate by Scale Factor of 2 A (, ) B (, ) C (, ) Directions: Plot the original points as indicated. Connect the points to make a right triangle. Then, perform the given dilation. To be completed together in class: -4 8 4 8 4 2

6. Directions: Plot the original points as indicated. Connect the points to make a right triangle. Then, perform the given dilation. Original Coordinates: A (-4, 6)B (2, 6)C (2, 3) Dilate by Scale Factor of ½ A (, ) B (, ) C (, ) -2 3 1 3 1 1.5 Multiplying by ½ is the SAME as dividing by 2!!

7. Dilations Example 1:

8. Dilations

11. Your turn:

12. Dilations Your turn:

13. Soooo, when a figure is dilated by a scale factor GREATER than one, the image gets ________________________. However, when a figure is dilated by a scale factor LESS than one (fraction), the image gets __________________________________. BIGGER smaller

14. A.Scale factor of 2 and reflection over the y-axis. B.Scale factor of 3 and reflection over the x-axis. C.Scale factor of 2 and reflection over the x-axis. D.Scale factor of 3 and reflection over the y-axis.

15. A.Scale factor of 1 B.Scale factor of 2 C.Scale factor of ½ D.Scale factor of 3