Program to calculate Area Of Octagon

An octagon is a polygon with eight sides. To calculate the area of octagon the following formula is used,

Area of octagon = ((a²*2) / *tan (22.5°)) = ((2*a*a)(1+√2))

Code Logic, The area of a polygon with eight side is calculated by using the above formula. The expression uses sqrt function to find the square root of 2. The value of expression is evaluated as a floating point value that is put into the float area variable.

Example

 Live Demo

#include <stdio.h>
#include <math.h>
int main(){
   int a = 7;
   float area;
   float multiplier = 6.18;
   printf("Program to find area of octagon 
");
   printf("The side of the octagon is %d 
", a);
   area = ((2*a*a)*(1 + sqrt(2)));
   printf("The area of Enneagon is %f 
", area);
   return 0;
}

Output

Program to find area of octagon
The side of the octagon is 7
The area of Enneagon is 236.592926