// header files
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

// local constants
#define EDGE_LENGTH_MULTIPLIER 5
// this volume is in centimeters
#define TOP_FRACTION 5*(3 + sqrt(5))
#define BOTTOM_FRACTION 12

/*
Name: Volume of Icosahedron
Process: Given an edge of an Icosahedron, calculate the volume of the shape. 
                               Uses a formula found on Google to calculate this.
Function input/parameters: NONE
Function output/parameters: NONE
Function output/returned: NONE
Device input/---: NONE
Device output/---: NONE
Dependencies: included by standard libraries
*/
int main()
{
    // define local variables
    double icosahedronVol;
    // do calculations
    icosahedronVol = (TOP_FRACTION / BOTTOM_FRACTION) * 
     (EDGE_LENGTH_MULTIPLIER * EDGE_LENGTH_MULTIPLIER * EDGE_LENGTH_MULTIPLIER);
    // display results
    printf("An Icosahedron with edge length %d cm has volume %f cm.\n", 
                                        EDGE_LENGTH_MULTIPLIER, icosahedronVol);
    // return success
    return 0;
}