# Largest right circular cylinder within a cube

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

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

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



Output:

98.125

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