1. september 14, 2009 Week 2 Day 5

2. An informal Introduction to Geometry

3. How many lines of symmetry to these regular polygons have? Do you see a pattern? opener

5. symmetric When you can fold a figure in half so that the two halves fit exactly on top of each other, the shape is symmetric. line of symmetry The line that contains the fold

6. The horizontal line through the second T is not a line of symmetry vertical line of symmetry

7. Symmetry

8. To be a line of symmetry, the shape must have two halves that match exactly. When you trace a heart onto a piece of folded paper, and then cut it out, the two half hearts make a whole heart. The two halves are symmetrical.

9. Which of these flags have a line of symmetry? United States of AmericaCanada MarylandEngland

10. What about these math symbols? Do they have symmetry?

11. # 1. Which other letters are symmetric? Which letters are both horizontally symmetric and vertically symmetric? solution next slide # 2. Describe the lines of symmetry of a circle. any line through the center of the circle

12. You can look to see if your name has symmetrical letters in it too! A B C D E FG H I J K L M N O P Q R S T U V W X Y Z Infinite number

18. p. 10 # 6 p. 14 # 5 These two problems will be online on Mr. Patel’s school page.

19. p.10 # 6

20. p.14 # 5