1. Symmetry

2. We find it in architecture…
…on a large scale…

3. …and on an every day scale

4. We find it in nature…

5. We find it in ancient things…

6. We find it in art…

7. We find it in optical illusions…
Symmetry is all around us

8. Based on all the pictures you just saw….
Try to define symmetry in your own words before clicking to the next slide.

9. So…how can we define symmetry?
If an object is balanced and can fit into itself by reflection, rotation or translation – it has symmetry
An object can have
line symmetry, or
rotational symmetry
Symmetry is related to motion geometry in that the object can be “moved”

10. Line symmetry
Line symmetry occurs where an object can be divided into mirror images.
This line is sometimes called a line of reflection or an axis of symmetry
The line can be vertical, horizontal or oblique (slanted)
An object can have one or more lines of symmetry – or none.

11. Examples of line symmetry

12. More examples of line symmetry
E U

13. Rotation symmetry

14. Rotation symmetry

15. Based on the three pictures you just saw…
Try to define rotational symmetry in your own words before clicking to the next slide.

16. Rotational symmetry…
When an object or shape can be spun around its center of rotation, AND fit into its original outline more than once in a complete turn.
This design fits into itself 10 times

17. Makes sure you have your notes to show me tomorrow!