CLASS-7
POLYGON - NONAGONS

NONAGONS -

A nonagon is a polygon with nine sides and nine angles. Here are some key properties and details about nonagons:

Types of Nonagons:-

  1. Regular Nonagon:- All sides are of equal length.All internal angles are equal, with each angle measuring 140°.A regular nonagon has symmetrical properties and can be inscribed in a circle.
  2. Irregular Nonagon:- The sides and angles are not necessarily equal, resulting in an asymmetrical shape.


Area Formula for a Regular Nonagon:-

The area A of a regular nonagon with side length s can be calculated using this formula:

                9              π

        A = ------ s²cot⁡ (-----) 

                4               9

This formula helps calculate the area based on the side length and the cotangent of the angle.


Other Properties:-

  • The perimeter of a regular nonagon is simply nine times the length of one side:-

                 Perimeter = 9 × s

  • The sum of the internal angles of any nonagon is always 1,260°, regardless of whether it's regular or irregular.


Examples of Nonagons in Real Life:-

  • Architecture:- Nonagons can sometimes be found in architectural designs, especially in floor plans and towers, as the shape is visually appealing and unique.
  • Decorative Art:- Nonagonal patterns might appear in tiling, mosaics, and other forms of design, especially in traditional or geometric art.