cube.ddl

#ifndef __cube
#define __cube

#include "body.h"

class cube : public body {
public:
  cube (float);
  char* identify();
  float GetVolume();
  float GetSurface();

protected:
  // a cube has just one length to fully describe it...
  float length;

};
#endif

cube.C

#include <iostream.h>
#include "cube.h"

char* cube::identify() { return "Cube"; };

float cube::GetVolume()
{
  //  volume is length**3 
  return length*length*length;
}


float cube::GetSurface()
{
  // 6 square sides of length
  return 6.*length*length;
}

cube::cube(float x)
{
  length = x;
}