程序计算八面体

给定八面体的侧面，然后计算八面体的体积。
例子：

Input : 3
Output : 12.7279

Input : 7
Output : 161.692

普通的八面体具有八个面，十二个边缘和六个顶点。它有八个三角形，两个三角形的边长相等，实际上两个底面相交的方形金字塔。

图片来源：Wikimedia

Properties of Octahedron: 
Number of faces: 8 
Number of edges: 12 
Number of vertices: 6 
Volume = √2/3 × a³ where a is the side of Octahedron 
 

CPP

// CPP Program to calculate
// volume of Octahedron
#include 
using namespace std;
 
// utility Function
double vol_of_octahedron(double side)
{
    return ((side*side*side)*(sqrt(2)/3));
}
 
// Driver Function
int main()
{
    double side = 3;
    cout << "Volume of octahedron ="
         << vol_of_octahedron(side)
         << endl;
}

Java

// Java Program to calculate
// volume of Octahedron
 
import java.io.*;
class GFG
{
    public static void main (String[] args)
      {
          // Driver Function
         double side = 3;
        System.out.print("Volume of octahedron = ");
        System.out.println(vol_of_octahedron(side));
 
      }
 
    // utility Function
    static double vol_of_octahedron(double side)
      {
         return ((side*side*side)*(Math.sqrt(2)/3));
      }
}
 
// This code is contributed
// by Azkia Anam.

Python3

# Python3 Program to calculate
# volume of Octahedron
 
import math
 
# utility Function
def vol_of_octahedron(side):
    return ((side*side*side)*(math.sqrt(2)/3))
 
# Driver Function
side = 3
print("Volume of octahedron =",
      round(vol_of_octahedron(side),4))
 
# This code is contributed
# by Azkia Anam.

C#

// C# Program to calculate
// volume of Octahedron
using System;
 
class GFG
{
    public static void Main ()
    {
        // Driver Function
        double side = 3;
        Console.Write("Volume of octahedron = ");
        Console.WriteLine(vol_of_octahedron(side));
 
    }
 
    // utility Function
    static double vol_of_octahedron(double side)
    {
        return ((side*side*side)*(Math.Sqrt(2)/3));
    }
}
 
// This code is contributed
// by vt_m.

Javascript

// javascript Program to calculate
// volume of Octahedron
 
// utility Function
function vol_of_octahedron( side)
{
    return ((side*side*side)*(Math.sqrt(2)/3));
}
 
// Driver Function
    let side = 3;
    document.write("Volume of octahedron = " +
    vol_of_octahedron(side).toFixed(4));
     
    // This code is contributed by gauravrajput1

输出：

Volume of octahedron = 12.7279