Symmetry

1. Symmetry Rotation Irma Crespo 2010

2. Warm Up http://www.haelmedia.com/OnlineActivities_txh/mc_txh4_001.html Irma Crespo 2010

3. Fast Fact on Rotation 90º 0º counterclockwise 180º 270º

4. Fast Fact on Rotation 90º 180º clockwise 0º 270º

5. 90º 180º 0º Rotational Symmetry • A figure has rotational symmetry if it can be rotated or turned less than 360º about its center so the figure looks exactly as it does in its original position. rotational symmetry at 180º

6. Rotational Symmetry • Simply means, if you turn a figure around before a complete turn (360º) and it looks exactly the same, then, it has rotational symmetry. 180º turn original position 90º turn rotational symmetry at 180º

7. Has Rotational Symmetry or Has No Rotational Symmetry

8. Which of these is not rotational symmetry? Ambigrams

9. Use of Symmetry http://www.teachers.ash.org.au/mikemath/movies/symmetry1.html

10. Summary • When an image is turned less than 360º and it looks exactly the same as it was when it was in its original position, there is rotational symmetry. • We learned two kinds of symmetry: line symmetry and rotational symmetry.

11. Exit Slip • Explain rotational symmetry. If you wish, you can differentiate it with line symmetry. • Your explanation has to be in complete sentences. • This is a one-point extra credit.

12. Complete the practice worksheet. Skills Practice: Lesson 6-5, Page 33/36 Work with a partner or on your own. Submit completed worksheet for grading. Solutions are discussed the next day. Practice Worksheet

13. PowerPoint created by Irma Crespo. University of Michigan-Dearborn, School of Education. Winter 2010.