1. Pretest  Clear everything off your desk except for a pencil and calculator. Pretest

2. What Lies Behind “Same Shape” Module 3 LP1

3. Similarity Two geometric figures are said to be similar if they have the same shape but not necessarily the same size.

4. The Avengers http://viewpure.com/-KekWFB4EPE

5. Two geometric figures are said to be similar if they have the same shape but not necessarily the same size. Using this informal definition, which of the following pairs of figures show similarity? Explain.

7. Dilation A dilation is a transformation that changes the size of an image. The scale factor (r) measures how much larger or smaller the image is.

8. Remember… Distance on a number line.

9. Distance on a number line What is the distance between points M and I? What is the distance between points A and H? What is the distance between points A and N? MATH I S F U N 8 units 4 units 14 units

10. Absolute Value What is the distance between points M and I? What is the distance between points A and H? What is the distance between points A and N? MATH I S F U N

11. Definition of Dilation

12. Example 20 inches

13. Practice

14. Visual http://www.mathopenref.com/dilate.html

15. With scale factor r … A figure shrinks in size when ________________. A figure is magnified (made larger in size) when ____________. When _________ the figure is congruent.

16. |′|=|| Where:  r is the scale factor  is length of the original segment  ′ is length of the dilated segment