Nonagon Area Calculator

Calculate the area, perimeter, and other properties of regular and irregular nonagons (9-sided polygons).

Nonagon Configuration

Regular Nonagon Properties

Length of each side of the regular nonagon

Quick Reference

Interior Angle:
140°
Central Angle:
40°
Exterior Angle:
40°
Diagonals:
27

Nonagon Visualization

About Nonagons

What is a Nonagon?

A nonagon (also called an enneagon) is a polygon with nine sides and nine vertices. In a regular nonagon, all sides are equal in length and all interior angles are equal (140°). Nonagons appear in architecture, art, and various geometric applications.

Key Properties

Regular Nonagon

  • 9 equal sides and angles
  • Interior angle: 140°
  • Central angle: 40°
  • Sum of interior angles: 1260°
  • Number of diagonals: 27

Irregular Nonagon

  • 9 sides of varying lengths
  • 9 angles of varying measures
  • Sum of interior angles: 1260°
  • Area calculated using shoelace formula
  • Can be convex or concave

How to Use This Calculator

  1. Choose between regular or irregular nonagon
  2. For regular: Select input method (side length, radius, area, etc.)
  3. For irregular: Enter the coordinates of all 9 vertices
  4. Click "Draw Nonagon" to visualize the shape
  5. Click "Calculate Nonagon" to get detailed measurements
  6. View area, perimeter, and other geometric properties

Input Methods for Regular Nonagon

  • Side Length: Length of each side of the regular nonagon
  • Circumradius (R): Radius of the circumscribed circle
  • Inradius (r): Radius of the inscribed circle
  • Area: Total area of the nonagon
  • Perimeter: Total length around the nonagon

Mathematical Formulas

Area (regular):
Circumradius:
Inradius:

Applications

  • Architecture: Building design and floor plans
  • Art and Design: Decorative patterns and logos
  • Engineering: Structural components and mechanical parts
  • Mathematics: Geometric studies and polygon theory
  • Games: Board game design and puzzle creation

Example Calculations

Try These Examples:

  • Regular nonagon with side length 5 units
  • Regular nonagon with circumradius 10 units
  • Irregular nonagon with custom vertex coordinates