# Polygons

We are using polygons in our life often. Let us see about it in detail. Polygons can be classified according to their sides.

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Number of sides |
Example | Name of the polygons |

3 | Triangle | |

4 | Quadrilateral | |

5 | Pentagon | |

6 | Hexagon | |

7 | Heptagon | |

8 | Octagon | |

9 | Â |
Nonagon |

10 | Decagon |

**Parts of Polygons :**

**(1)** Edges : The line segment joining two vertices of a polygon is called an edge or side.

**(2)Â **Diagonals : The line segment joining two non adjacent vertices of a polygon is called diagonal of the polygon.

**(3)Â **Types of PolygonsÂ

The sides and angles of polygons may or may not be equal. Based upon the nature of sides, angles and diagonals, polygons differ. They are regular, irregular, concave, and convex polygons. Let us see one by one.

# Regular Polygons

A polygon in which all sides are equal and all angles are equal is called regular polygon.Â

**Irregular Polygons :-**

Polygons which are not regular are called irregular polygons. That is, their sides and angles are not equal.

**Concave Polygons:-**

A polygon is said to be concave if all its diagonals lie inside the polygon.

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**Convex Polygons :-**

A polygon is said to be convex if at least one of the diagonal lies outside it.

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