1. How do you determine the number of lines of symmetry for this regular polygon?

2. In this lesson you will learn how to identify line symmetry in regular polygons by folding the figure into matching, or symmetrical parts.

3. Let’s Review Polygon

4. Regular Polygon

5. A Common Misunderstanding To determine the lines of symmetry you have to use horizontal, vertical and diagonal lines. I found all the lines of symmetry! X

6. Let’s Review Horizontal DiagonalVertical Line Symmetry

7. Core Lesson The equilateral triangle has 1 vertical line of symmetry.

8. The equilateral triangle has 2 diagonal lines of symmetry.

9. The equilateral triangle does not have a horizontal line of symmetry.

10. The equilateral triangle has 3 lines of symmetry. 1 vertical and 2 diagonal lines of symmetry.

11. A square has 2 diagonal lines of symmetry.

12. A square has one vertical line of symmetry.

13. A square has 1 horizontal line of symmetry.

14. A square has 4 lines of symmetry. There are 2 diagonals, 1 horizontal, and one vertical line of symmetry.

15. An equilateral triangle has 3 lines of symmetry and 3 congruent sides. A square has 4 lines of symmetry and 4 congruent sides.

16. A hexagon has 6 lines of symmetry. There is one horizontal line, one vertical line and 4 diagonal lines of symmetry.

17. In this lesson you have learned how to identify line symmetry in regular polygons by folding the figure into matching, or symmetrical parts.