Given a sphere of radius . The task is to find volume of the biggest right circular cylinder that can be inscribed within it.**Examples**:

Input: R = 4Output: 77.3495Input: R = 5Output: 151.073

**Approach**:

let **r** be the radius of the right circular cylinder, and **h** be it’s height.

Volume of the cylinder, **V = π*r ^{2}*h**

Also,

**r**

^{2}= R^{2}– h^{2}or,

**V = π*(R**

^{2}– h^{2})*hor,

**dV/dh = π*(R**

^{2}– 3*h^{2})Setting it to zero, we get

**h = R/√3**

So,

**Vmax = 2πR**

^{3}/3√3Below is the implementation of the above approach:

## C++

`// C++ Program to find the biggest right circular cylinder` `// that can be fit within a sphere` `#include <bits/stdc++.h>` `using` `namespace` `std;` `// Function to find the biggest right circular cylinder` `float` `cyl(` `float` `R)` `{` ` ` `// radius cannot be negative` ` ` `if` `(R < 0)` ` ` `return` `-1;` ` ` `// volume of cylinder` ` ` `float` `V = (2 * 3.14 * ` `pow` `(R, 3)) / (3 * ` `sqrt` `(3));` ` ` `return` `V;` `}` `// Driver code` `int` `main()` `{` ` ` `float` `R = 4;` ` ` `cout << cyl(R) << endl;` ` ` `return` `0;` `}` |

## Java

`// Java Program to find the biggest` `// right circular cylinder that can` `// be fit within a sphere` `import` `java.io.*;` `class` `GFG` `{` `// Function to find the biggest` `// right circular cylinder` `static` `float` `cyl(` `float` `R)` `{` ` ` `// radius cannot be negative` ` ` `if` `(R < ` `0` `)` ` ` `return` `-` `1` `;` ` ` `// volume of cylinder` ` ` `float` `V = (` `float` `)((` `2` `* ` `3.14` `* Math.pow(R, ` `3` `)) /` ` ` `(` `3` `* Math.sqrt(` `3` `)));` ` ` `return` `V;` `}` `// Driver code` `public` `static` `void` `main (String[] args)` `{` ` ` `float` `R = ` `4` `;` ` ` `System.out.print( cyl(R));` `}` `}` `// This code is contributed by anuj_67..` |

## Python 3

`# Python 3 Program to find the biggest` `# right circular cylinder that can be` `# fit within a sphere` `import` `math` `# Function to find the biggest right` `# circular cylinder` `def` `cyl(R):` ` ` ` ` `# radius cannot be negative` ` ` `if` `(R < ` `0` `):` ` ` `return` `-` `1` ` ` `# volume of cylinder` ` ` `V ` `=` `((` `2` `*` `3.14` `*` `math.` `pow` `(R, ` `3` `)) ` `/` ` ` `(` `3` `*` `math.sqrt(` `3` `)));` ` ` `return` `float` `(V)` `# Driver code` `R ` `=` `4` `print` `(cyl(R))` `# This code is contributed` `# by PrinciRaj1992` |

## C#

`// C# Program to find the biggest` `// right circular cylinder that can` `// be fit within a sphere` `using` `System;` `class` `GFG` `{` `// Function to find the biggest` `// right circular cylinder` `static` `float` `cyl(` `float` `R)` `{` ` ` `// radius cannot be negative` ` ` `if` `(R < 0)` ` ` `return` `-1;` ` ` `// volume of cylinder` ` ` `float` `V = (` `float` `)((2 * 3.14 * Math.Pow(R, 3)) /` ` ` `(3 * Math.Sqrt(3)));` ` ` `return` `V;` `}` `// Driver code` `public` `static` `void` `Main ()` `{` ` ` `float` `R = 4;` ` ` `Console.WriteLine( cyl(R));` `}` `}` `// This code is contributed by shs` |

## PHP

`<?php` `// PHP Program to find the biggest right circular cylinder` `// that can be fit within a sphere` `// Function to find the biggest right circular cylinder` `function` `cyl(` `$R` `)` `{` ` ` `// radius cannot be negative` ` ` `if` `(` `$R` `< 0)` ` ` `return` `-1;` ` ` `// volume of cylinder` ` ` `$V` `= (2 * 3.14 * pow(` `$R` `, 3)) / (3 * sqrt(3));` ` ` `return` `$V` `;` `}` `// Driver code` ` ` `$R` `= 4;` ` ` `echo` `cyl(` `$R` `);` `// This code is contributed by shs` `?>` |

## Javascript

`<script>` `// javascript Program to find the biggest` `// right circular cylinder that can` `// be fit within a sphere` `// Function to find the biggest` `// right circular cylinder` `function` `cyl(R)` `{` ` ` `// radius cannot be negative` ` ` `if` `(R < 0)` ` ` `return` `-1;` ` ` `// volume of cylinder` ` ` `var` `V = ((2 * 3.14 * Math.pow(R, 3)) /` ` ` `(3 * Math.sqrt(3)));` ` ` `return` `V;` `}` `// Driver code` `var` `R = 4;` `document.write( cyl(R).toFixed(4));` `// This code contributed by shikhasingrajput` `</script>` |

**Output:**

77.3495

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