# Program to calculate are of Enneagon

Enneagon is a polygon with 9 sides and 9 internal angles. Enneagon is also known as Nonagon. A regular nonagon has an internal angle of 140 degrees each. Sum of interior angles of the nonagon is 1260 degree.
The center of the circumcircle is also taken as the center of the regular Nonagon.
The line segment drawn the perpendicular to a side of the Nonagon is called the Apothem and is represented by ‘a’.

``` Area ≈ 6.1818 * s * s
where s is side length.
```

Examples:

```Input : 6
Output :Area of Regular Nonagon = 222.5448

Input : 8
Output :Area of Regular Nonagon = 395.6352
```

## C++

```// CPP program to find area of a Hexagon
#include <iomanip>
#include <iostream>
#include <math.h>
using namespace std;

// Function to calculate area of nonagon
double Nonagon_Area(double s) {
return (6.1818 * s * s);
}

// driver function
int main() {
double s = 6; // Length of a side
cout << "Area of Regular Nonagon = " << std::setprecision(7)
<< Nonagon_Area(s);
return 0;
}
```

## Java

```// Java program to find area of a Hexagon
class Nonagon {

// Function for calculating the area of the nonagon
public static double Nonagon_Area(double s) {
return ((6.1818 * (s * s)));
}

// driver code
public static void main(String[] args) {
double s = 6; // Length of a side
System.out.print("Area of Regular Nonagon = " + Nonagon_Area(s));
}
}
```

## Python

```# python program to find area of a Hexagon
length = 6
Nonagon_area = 6.1818 * (length ** 2)
print("Area of regular Nonagon is = ", Nonagon_area)
```
Output:

```Area of Regular Nonagon = 222.5448
```

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