Polygon is a closed two-dimensional figure that is made up of joining line segments together. Here, we shall discuss about types of polygons.

**The classification of polygons is as follows:**

There are two main types of polygons on the basis of sides and angles:

- Regular Polygon
- Irregular Polygon

**Regular polygon** is the one in which all the sides are equal and all the interior angles are equal.

**Properties of a Regular Polygon****(1) **Sum of all exterior angles of a regular polygon is $360^{\circ}$.

**(2) **Each exterior angle of a regular polygon measures

$\frac{360^{\circ}}{n}$, where n is the number of sides.

**(3) **Sum of the interior and exterior angle at a pointÂ is $180^{\circ}$. Therefore, measure of each interior angle is given by:

Interior angle = $180^{\circ}$ - exterior angle.

= $180^{\circ} - $

$\frac{360^{\circ}}{n}$= $n \times $

$\frac{180^{\circ}}{n}$$ - 2 \times $

$\frac{180^{\circ}}{n}$= (n - 2)

$\frac{180^{\circ}}{n}$Following diagram shows a regular polygon:

**Irregular polygon** is the one that is not regular, i.e. the polygon in which all side are not equal and all angles are not same, is known as an irregular polygon. Following images illustrates an irregular polygon:

Polygons can be classified further on the basis on shapes

- Convex Polygon
- Concave Polygon
- Complex Polygon

**Convex polygon** has all the vertices outwards. Each interior angle of a convex polynomial is less than $180^{\circ}$. An example of convex polygon is shown below:

**Concave polygon** has at least one vertex pointing inwards. At least one interior angle of a concave polynomial measures greater than $180^{\circ}$. An example of concave
polygon is shown below:

**Complex polygon** is a polygon in which the one or more sides intersect the other. Complex polygon is an exception and breaks many rules which other types of polygons follow. An example of a complex polygon is a

**star polygon** which demonstrated below: