Polygon Calculator

Author: Henrick Yau
- 26 September 2026
| |

Calculators

Calculate various properties of regular polygons including area, perimeter, interior angles, and more. This calculator supports multiple calculation methods and provides visualisations with step-by-step explanations.

Select Calculation Method

Advanced Options

About Regular Polygons in Geometry

A regular polygon is a polygon that is equiangular (all angles are equal) and equilateral (all sides have the same length). Regular polygons are important in geometry, architecture, design, and many other fields.

Key Properties and Formulas
  • Number of Sides (n): The total count of sides and vertices in the polygon.
  • Side Length (s): The length of each side of the polygon.
  • Perimeter (P): P = n × s (The sum of all side lengths)
  • Interior Angle (θint): θint = (n − 2) × 180° / n (The angle inside the polygon at each vertex)
  • Exterior Angle (θext): θext = 360° / n (The angle formed by extending a side)
  • Inradius (r): r = s / (2 × tan(π/n)) (The radius of the inscribed circle)
  • Circumradius (R): R = s / (2 × sin(π/n)) (The radius of the circumscribed circle)
  • Area (A): A = (n × s²) / (4 × tan(π/n))
Common Regular Polygons
  • Triangle (n=3): Also known as an equilateral triangle.
  • Square (n=4): Has four equal sides and angles of 90°.
  • Pentagon (n=5): Has five equal sides and interior angles of 108°.
  • Hexagon (n=6): Has six equal sides and interior angles of 120°.
  • Octagon (n=8): Has eight equal sides and interior angles of 135°.
  • Decagon (n=10): Has ten equal sides and interior angles of 144°.
  • Dodecagon (n=12): Has twelve equal sides and interior angles of 150°.
Applications

Regular polygons have many practical applications:

  • Architecture: Building layouts, decorative elements, floor plans
  • Design: Logos, patterns, product shapes
  • Engineering: Mechanical parts, gear design, structural elements
  • Urban Planning: Traffic roundabouts, public spaces, park layouts
  • Nature: Many natural structures approximate regular polygons (honeycomb cells, crystal structures)
  • Traffic Signs: Stop signs are regular octagons

What this polygon calculator does

The Polygon Calculator is a handy tool designed to help you find various properties of regular polygons. With just a few inputs, you can calculate the area, perimeter, interior angles, and other important features. Whether you're a student, teacher, or just curious about shapes, this calculator simplifies your calculations and provides clear results.

How to Use the Polygon Calculator

This calculator offers different methods for calculation, so you can choose what works best for you. You can input the number of sides and side length, perimeter, area, inradius, or circumradius. The calculator adjusts to show only the fields you need, making it user-friendly. Just enter your values, and the tool does the rest!

Multiple calculation methods and visualisation

  • Multiple calculation methods: Choose from sides and length, perimeter, or area.
  • Step-by-step explanations: Understand how the results are calculated.
  • Visualisation options: See a diagram of your polygon for better understanding.
  • Customizable decimal places and angle units for accuracy.

Calculating Different Properties

You can find a wide range of properties using this calculator. For instance, you can determine the perimeter by using the number of sides and side length or calculate the area using the number of sides and the length of each side. This flexibility allows you to get the information you need quickly and effectively.

Educational Benefits of the Polygon Calculator

This tool is perfect for students learning about geometry. It helps reinforce concepts like the relationship between side length, perimeter, and area. With visual aids and detailed explanations, learners can grasp these mathematical ideas more easily. Teachers can also use it to create interactive lessons and engage their students.

Understanding Regular Polygons

Regular polygons are shapes with equal sides and angles. Some common examples include triangles, squares, and hexagons. Knowing the properties of these shapes is essential in geometry and has practical applications in architecture and design. The Polygon Calculator aids in exploring these properties in a simple, straightforward manner.

Real-world uses in architecture and design

  • Architecture: Design layouts and decorative features.
  • Engineering: Create parts and structures using polygon shapes.
  • Graphic Design: Develop logos and patterns that incorporate geometric shapes.
  • Urban Planning: Design public spaces like parks and roundabouts.

Why this tool suits geometry learners

Choosing the Polygon Calculator means you have an efficient and reliable tool at your fingertips. It saves time while providing accurate results and clear explanations. Whether you’re tackling homework, working on a project, or just exploring the world of polygons, this calculator is an invaluable resource for anyone interested in geometry.

Related Calculators