A polygon is a geometric figure with two dimensions (2D) and limited sides. The sides of a polygon comprise straight lines segments that meet at a connection point of end to end. Therefore, sides or edges are terms used to call the parts of a polygon.

Also, a point where two sides or edges meet is called a vertex or simply corners. At this meeting point, an angle forms. A famous example of a polygon is a triangle that has three sides.

Even though a circle is a plane figure, it doesn’t fall under polygons since it does not have sides or angles due to its curved shape. Therefore, it’s true to say that while polygons are 2D shapes, not all two-dimensional shapes are polygons.

### Types of Polygons

Besides understanding the basic definition of a pentagon to be 2D shapes, there’s more than what meets the eye. There are several and different types of polygons with categories that rely on the number of sides and level of the angles.

Some of the main categories of polygons consist of regular, irregular, concave, convex, quadrilateral, pentagon, and many more. Still, among the popular polygons are rectangles, squares, triangles, pentagons, hexagons, parallelograms, and rhombuses.

Let’s get into details of each polygon;

### Regular Polygon

When looking at a regular polygon, you will notice that all sides are equal. Moreover, all the interior angles have equivalent extents. A perfect example of this would be a square.

### Irregular Polygon

Unlike the regular type, irregular polygons have unequal sides and angles.

Concave pentagon

A concave polygon has one of the angles measuring over 180 degrees. Moreover, the vertices of a concave pentagon are visible inwards and outwards.

### Convex Polygon

In a convex polygon, the interior angle measures below degrees. Therefore, a convex is a direct opposite of a concave. Still, the vertices of a convex pentagon are external.

### Quadrilateral Polygon

Also called a four-sided polygon, it is relatively standard. Quadrilateral pentagon comes in different versions like rectangle, square, and parallelogram.

### Pentagon Polygon

Pentagon polygons have six sides. Most importantly, you should know that the five sides of the pentagon remain in equal length. A regular pentagon can also be in the category of a pentagon polygon.

### What Are The Special Types Of Polygons?

As observed above, quadrilaterals are polygons that have four sides. However, quadrilaterals that come with the same sized sides and angles are called squares.

On the other hand, if a pentagon consists of four right-angled corners, yet two opposite sides appear more extended than the different opposite two sides, it is called a rectangle.

Still, there are other different types of triangles with distinct names such as;

An equilateral triangle: It falls under the regular pentagon because it has all equal sides and angles.

An isosceles triangle: This comes under the irregular polygons because the sides come in different sizes.

A right-angle triangle: It derives its name from one of its angles that is right-angled.

Generally, polygons can either be simple or complex. A simple pentagon is a basic shape with a single boundary and no crossing lines, while a complex pentagon has overlapping sides and more edges.