9.5 : Symmetry

1. 9.5 : Symmetry I can identify line and rotational symmetries in two‐dimensional figures. I can identify plane and axis symmetries in three‐dimensional figures.

2. If the images to the right describe symmetry, in your own words, define symmetry:

3. Vocabulary!

4. Example 1: State whether the object appears to have line symmetry. Write yes or no. If so, draw all lines of symmetry, and state their number.

5. Vocabulary!

6. Vocabulary!

7. Example 2: State whether the figure has rotational symmetry. Write yes or no. If so, locate the center of symmetry, and state the order and magnitude of symmetry.

8. You Try! State whether the figure has rotational symmetry. Write yes or no. If so, locate the center of symmetry, and state the order and magnitude of symmetry.

9. You Try! State whether the figure has rotational symmetry. Write yes or no. If so, locate the center of symmetry, and state the order and magnitude of symmetry.

10. Example 3: Determine whether the entire word has line symmetry and whether it has rotational symmetry. Identify all lines of symmetry and angles of rotation that map the entire word onto itself.

11. Three Dimensional Symmetries

12. Example 4: State whether the figure has plane symmetry, axis symmetry, both, or neither. a) b)

13. You Try! State whether the figure has plane symmetry, axis symmetry, both, or neither. 1.

14. You Try! State whether the figure has plane symmetry, axis symmetry, both, or neither. 2.

15. You Try! State whether the figure has plane symmetry, axis symmetry, both, or neither. 3.

16. You Try! State whether the figure has plane symmetry, axis symmetry, both, or neither. 4.

17. You Try! State whether the figure has plane symmetry, axis symmetry, both, or neither. 5.

18. You Try! State whether the figure has plane symmetry, axis symmetry, both, or neither. 6.

19. Homework: pg. 666, #9, 10, 12, 17, 19, 20, 27 – 33