# Largest right circular cylinder within a cube

• Last Updated : 05 Aug, 2022

Given a cube of side length a. The task is to find the volume of biggest right circular cylinder that can be inscribed within it.
Examples:

```Input :  a = 4
Output : 50.24

Input : a = 5
Output : 98.125``` Approach
Let:

• The height of the cylinder is h.
• Radius of the cylinder be r.

From the diagram it is clear that:

• The height of the cylinder = side of cube
• Radius of the cylinder = side of the cube/2

So,

```h = a
r = a/2```

Below is the implementation of the above approach:

## C++

 `// C++ Program to find the biggest right``// circular cylinder that can be fit within a cube``#include ``using` `namespace` `std;` `// Function to find the biggest right circular cylinder``float` `findVolume(``float` `a)``{``    ``// side cannot be negative``    ``if` `(a < 0)``        ``return` `-1;` `    ``// radius of right circular cylinder``    ``float` `r = a / 2;` `    ``// height of right circular cylinder``    ``float` `h = a;` `    ``// volume of right circular cylinder``    ``float` `V = 3.14 * ``pow``(r, 2) * h;` `    ``return` `V;``}` `// Driver code``int` `main()``{``    ``float` `a = 5;` `    ``cout << findVolume(a) << endl;` `    ``return` `0;``}`

## Java

 `// Java Program to find the biggest right``// circular cylinder that can be fit within a cube` `import` `java.io.*;` `class` `GFG {``  `  `// Function to find the biggest right circular cylinder`` ``static` `float` `findVolume(``float` `a)``{``    ``// side cannot be negative``    ``if` `(a < ``0``)``        ``return` `-``1``;` `    ``// radius of right circular cylinder``    ``float` `r = a / ``2``;` `    ``// height of right circular cylinder``    ``float` `h = a;` `    ``// volume of right circular cylinder``    ``float` `V = (``float``)(``3.14` `* Math.pow(r, ``2``) * h);` `    ``return` `V;``}` `// Driver code`  `    ``public` `static` `void` `main (String[] args) {``            ``float` `a = ``5``;` `    ``System.out.print(findVolume(a));``    ``}``}``// This code is contributed by anuj_67..`

## Python3

 `# Python3 Program to find the biggest``# right circular cylinder that can be``# fit within a cube` `# Function to find the biggest right``# circular cylinder``def` `findVolume(a) :` `    ``# side cannot be negative``    ``if` `(a < ``0``) :``        ``return` `-``1` `    ``# radius of right circular cylinder``    ``r ``=` `a ``/` `2` `    ``# height of right circular cylinder``    ``h ``=` `a` `    ``# volume of right circular cylinder``    ``V ``=` `3.14` `*` `pow``(r, ``2``) ``*` `h` `    ``return` `V` `# Driver code``if` `__name__ ``=``=` `"__main__"` `:` `    ``a ``=` `5` `    ``print``(findVolume(a))` `# This code is contributed by Ryuga`

## C#

 `// C# Program to find the biggest right``// circular cylinder that can be fit within a cube` `using` `System;``class` `GFG {`  `// Function to find the biggest right circular cylinder``static` `float` `findVolume(``float` `a)``{``    ``// side cannot be negative``    ``if` `(a < 0)``        ``return` `-1;` `    ``// radius of right circular cylinder``    ``float` `r = a / 2;` `    ``// height of right circular cylinder``    ``float` `h = a;` `    ``// volume of right circular cylinder``    ``float` `V = (``float``)(3.14 * Math.Pow(r, 2) * h);` `    ``return` `V;``}` `// Driver code`  `    ``public` `static` `void` `Main () {``            ``float` `a = 5;` `   ``Console.WriteLine(findVolume(a));``    ``}``}``// This code is contributed by anuj_67..`

## PHP

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## Javascript

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Output:

`98.125`

Time Complexity: O(1)

Auxiliary Space: O(1)

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