Double Math

9 Sided Polygon (Nonagon) – Nine Sided Shape

What is a Nine Sided Shape?

9 Sided Polygon

With nine straight sides that meet at nine corners make a polygon that is called a Nonagon. Nonagon is a 2D nine sided shape that belongs to the family. The word  “nonagon ” comes from the Latin word  “nona “, meaning nine, and  “gon “, meaning sides. So it literally means  “nine-sided shape “.

class result

There are 9 straight sides and 9 vertices connecting these straight sides in a nonagon. The Sum of all the interior angles of a nine-sided polygon is equal to 1260 degrees.

In Greek, a nonagon is called an enneagon, which means “nine corners”.

Types of (Nonagon) 9-Sided Shape

There are two types of nonagon.

  • Regular Nonagon
  • Irregular Nonagon

Regular Nonagon

  • It is a two-dimensional shape.
  • It has nine vertices.
  • Each interior angle is at 140^\circ and the sum of these interior angles is 1260^\circ.
  • It’s all straight lines that have equal lengths.
  • It has an exterior angle equal to 360 degrees.
  • The regular nonagon has a symmetrical appearance and is considered a highly geometrically structured shape. It’s often used to demonstrate principles of symmetry and equality in geometry.
Nine Sided Shape

Irregular Nonagon

  • The sum of all of its interior angles is 1260^\circ degrees.
  • Angles at varying degrees.
  • It is a nine-sided, two-dimensional shape
  • Additionally, it has straight lines
  • The sides are not equal in length.
  • Irregular nonagon does not have the symmetrical properties of a regular nonagon and can take on various shapes, making it more versatile in appearance.
Nine Sided Shape

9 sided Shapes in daily life and their role.

Nine sided Shape or nonagon used in various fields for example Stop sign is used to control traffic

Football: Some footballs are in nonagon shape that players use for better playing.

Garden: In gardening, a nonagon shape might be considered for a better view.

Area of Nine sided Shape (Nonagon) Examples

Question #1: Find the area of a regular nonagon with a side length of 8 units.

The formula for the area of regular Nonagon is


here l is the length of each side of nonagon(regular)


Area=\frac94\;8^2\;cot\left(\frac{\mathrm\pi}9\right)</p> <p>[katex] Area=\frac94\;\left(64\;\right)\left(3.0777\right)

Area= 554.784 square units