Polygon is part of our everyday life. We use things which are in any form or shape, most of them are polygons. In this chapter, we will explore elaborately about polygon and its types.
A polygon is a two-dimensional shape formed with more than three straight lines. For example, a closed figure formed with three straight lines is termed as triangle whereas a shape formed with four straight lines is known as a quadrilateral. It is formed with only straight lines; if any curved line is used to form a closed figure than it will not be termed as a polygon.
Polygon is basically any closed shape which is formed with three or more straight lines. There is no limit in how many sides will be there in a polygon, it can possess infinite sides, they can have 10 sides or more sides.
Browse more Topics under Understanding Quadrilaterals
- Angle Sum Property of Polygons
- Properties of Trapezium and Kite
- Properties of Parallelogram, Rhombus, Rectangle and Square
Types of Polygon
A polygon can be classified on the basis of a number of sides and measure of angles. First, we will discuss on the basis of the measure of angles–
Classified by Measuring the Angles
- Regular Polygon: Polygon in which all the sides of angle are same and all the interior angle of the polygon are equal is called regular polygon.
- Irregular Polygon: The polygon in which is not regular a polygon is known as Irregular Polygon. Irregular polygons do not have equal sides and measure of angles.
- Convex Polygon: The polygon whose measure of an interior angle is less than 180° is termed as a convex polygon. The vertices of a convex polygon are always outwards.
- Concave Polygons: In concave polygons, at least one angle measures more than 180°. Those polygons which are not convex are concave polygons.
- Quadrilateral Polygons: Quadrilateral polygons are the polygons which are four-sided or with four angles i.e. quadrangle. Every polygon which forms four angles is known as quadrilateral polygons.
- Pentagon Polygons: The polygon which consists of five sides is termed as pentagon polygon.
Classified by Measuring the Sides
Name of a polygon is termed according to the number of sides they have. Though polygon can have an infinite number of sides and can be termed according to the number of sides suppose a polygon consist. Suppose a polygon consist of 3 sides then it is known as a triangle, but if a polygon consists of 333 sides it will be known as 333-gon.
- Triangle: The three-sided polygon is known as the triangle.
- Quadrilateral: Any figure which is a closed four-sided figure is known as a quadrilateral.
- Pentagon: The closed figure which is formed by five straight lines is known as a pentagon.
- Hexagon: The six-sided polygon is known as a hexagon.
- Heptagon: The polygon with seven sides is termed as a heptagon.
- Octagon: As the name says, the Eight-sided polygon is known as Octagon.
- Nonagon: The polygon which possesses nine straight lines is known as nonagon.
- Decagon: The closed figure made with ten straight lines is termed as decagon polygon.
The most common type of polygons is Triangle, Rhombus, Kite, Trapezium etc. With the above details, it will now be easier for you to determine the shapes.
Solved Question for You
Question 1: A rectangle is also a kind of parallelogram discuss why?
Answer : A rectangle is also a parallelogram because all its opposite sides are parallel to each other. Despite forming an angle of 90°, rectangle due to its parallel sides can be said to be a parallelogram.
Question 2: How to define the different types of polygons?
Answer: The polygons are also defined by the number of sides they are made of. There are so many types of polygons, for instance, Triangles that have 3 sides, then there is Quadrilateral that has 4 sides and there are also some polygons that have more than 4 sides, and so many other types of polygons are also there.
Question 3: What are the names of the different types of polygons?
Answer: Inside the geometry, we have multiple kinds of polygons that can be classified as the simplex or the complex polygon. Some of them are classified as the concave or convex polygon and some as regular or irregular polygons as well. There are various types in regular polygons like quadrilaterals, pentagons, Hexagons, Heptagons, Octagons, Nonagons, Decagons, etc.
Question 4: Which polygon is the simplest polygon?
Answer: A simple polygon is that polygon which does not intersect itself and doesn’t have holes. This defines that it is of flat shape comprising straight, non-intersecting lines or “sides” that are linked pairwise to form a single closed route.
Question 5: What is the unique polygon theorem?
Answer: The Unique Polygon Theorem says that “All the regular polygons that have a similar number of sides are alike.”