# Lines of Symmetry of Plane Shapes

## Line of Symmetry

Here my dog "Flame" has her face The white line down the center is the |

## Folding Test

You can find if a shape has a Line of Symmetry by** folding it**.

When the folded part sits perfectly on top (all edges matching), then the fold line is a Line of Symmetry.

Here I have folded a rectangle one way, and **it didn't work**.

So this is **not** a Line of Symmetry

But when I try it this way, it **does work** (the folded part sits perfectly on top, all edges matching):

So this **is** a Line of Symmetry

## Triangles

A Triangle can have **3**, or **1** or **no** lines of symmetry:

Equilateral Triangle(all sides equal, all angles equal) | Isosceles Triangle(two sides equal, two angles equal) | Scalene Triangle(no sides equal, no angles equal) | ||

3 Lines of Symmetry | 1 Line of Symmetry | No Lines of Symmetry |

## Quadrilaterals

Different types of Quadrilaterals (a 4-sided plane shape):

Square(all sides equal, all angles 90°) | Rectangle(opposite sides equal, all angles 90°) | Irregular Quadrilateral | ||

4 Lines of Symmetry | 2 Lines of Symmetry | No Lines of Symmetry |

Kite | Rhombus(all sides equal length) | |

1 Line of Symmetry | 2 Lines of Symmetry |

## Regular Polygons

A regular polygon has all sides equal, and all angles equal:

An Equilateral Triangle (3 sides) has 3 Lines of Symmetry | ||

A Square (4 sides) has 4 Lines of Symmetry | ||

A Regular Pentagon (5 sides) has 5 Lines of Symmetry | ||

A Regular Hexagon (6 sides) has 6 Lines of Symmetry | ||

A Regular Heptagon (7 sides) has 7 Lines of Symmetry | ||

A Regular Octagon (8 sides) has 8 Lines of Symmetry |

And the pattern continues:

- A regular polygon of
**9**sides has**9**Lines of Symmetry - A regular polygon of
**10**sides has**10**Lines of Symmetry - ...
- A regular polygon of
**"n"**sides has**"n"**Lines of Symmetry

## CircleA line (drawn at any angle) that goes through its center is a Line of Symmetry. So a Circle has |