Program to calculate Area Of Octagon

A regular octagon is a closed figure with sides of the same length and internal angles of the same size. It has eight lines of reflective symmetry and rotational symmetry of order 8. The internal angle at each vertex of a regular octagon is 135°. The central angle is 45°.

Properties :

Convex polygon, Equilateral polygon, Isogonal figure, Isotoxal figure, Cyclic. Formula :

Area : 2 × (side length)² × (1+sqrt(2))

Examples :

Input : side = 3
Output : Area of Regular Octagon = 43.4558

Input : side = 4
Output : Area of Regular Octagon = 77.2548

C++

 // CPP program to find area of octagon #include using namespace std;    // Utility function double areaOctagon(double side) {     return (float)(2 * (1 + sqrt(2)) *                     side * side); }    // Driver Code int main() {     double side = 4;     cout << "Area of Regular Octagon = "          << areaOctagon(side) << endl;     return 0; }

Java

 // Java Program to find  // area of Octagon. import java.io.*;    class GFG {        // utility function     static double areaOctagon(double side)     {     return (float)(2 * (1 + Math.sqrt(2))                            * side * side);     }            // driver code     public static void main(String arg[])     {         double side = 4;         System.out.print("Area of Regular Octagon = "                             + areaOctagon(side));     } }    // This code is contributed by Anant Agarwal.

Python3

 # Python3 program to  # find area of octagon    import math    # Utility function def areaOctagon(side):     return (2 * (1 + (math.sqrt(2))) * side * side)    # Driver function side = 4 print("Area of Regular Octagon =",        round(areaOctagon(side), 4))    # This code is contributed # by Azkia Anam.

C#

 // C# Program to find  // area of Octagon. using System;    class GFG {      // utility function     static double areaOctagon(double side)     {     return (float)(2 * (1 + Math.Sqrt(2))                          * side * side);     }            // Driver code     public static void Main()     {         double side = 4;         Console.WriteLine("Area of Regular Octagon = "                           + areaOctagon(side));     } }    // This code is contributed by vt_m.

PHP



Output :

Area of Regular Octagon = 77.2548