// Dimensional calulator. v6.2
// Dimension.c - 320mb 16 - 6 - 2004



#include <iostream.h>
#include <math.h>


const float pi = 3.141592653589793238;
int option,pause;
float rad,area,circum,diam = 0;
double radsq,x = 0;
char radmsg[] ="\nThe radius of this circle is ";
char cirmsg[] ="\nThe circumference of this circle is ";
char diamsg[] ="\nThe diameter of this circle is ";
char aremsg[] ="\nThe area of this circle is ";

int main()
{
   cout << "Calculate Circle Dimensions v6.2. by Stanley Clark\n\n";
   cout << "Please choose a valid option from below ... \n\n";
   cout << "	To find the properties from the radius type: 1\n";
   cout << "	To find the properties from the diameter type: 2\n";
   cout << "	To find the properties from the circumference type: 3\n";
   cout << "	To find the properties from the area type: 4\n";
   cout << "	To exit please type: 5 \n\n";
   
   
   cin >> option;

   switch (option)
{
		case 1:
   cout << "\nPlease enter the radius of a circle in milimetres? ";
	cin >> rad;
   cout << "\nYou entered the radius as " << rad << " mm....\n";
   diam = rad * 2;     // Calculate diameter
	cout << diamsg << diam << " mm\n";
   circum = 2 * pi * rad;     // Calculate circumference
   cout << cirmsg << circum << " mm\n";
   area = rad * rad * pi;     // Calculate area
   cout << aremsg << area << " mm^2\n";
   break;
   
   	case 2:
   cout << "\nPlease enter the diameter of a circle in milimetres? ";
	cin >> diam;
   cout << "\nYou entered the diameter as " << diam << " mm....\n";
   rad = diam / 2;    // Calculate radius
	cout << radmsg << rad << " mm\n";
   circum = pi * diam;   // Calculate circumference
   cout << cirmsg << circum << " mm\n";
   area = rad * rad * pi;   // Calculate area
   cout << aremsg << area << " mm^2\n";
   break;

      case 3:
   cout << "\nPlease enter the circumference of a circle in milimetres? ";
	cin >> circum;
   cout << "\nYou entered the circumference as " << circum << " mm....\n";
   rad = circum / 2 / pi;     // Calculate radius
   cout << radmsg << rad << " mm\n";
   diam = rad * 2;     // Calculate diameter
	cout << diamsg << diam << " mm\n";
   area = rad * rad * pi;     // Calculate area
   cout << aremsg << area << " mm^2\n";
   break;

      case 4:
   cout << "\nPlease enter the area of a circle in milimetres squared? ";
	cin >> area;
   cout << "\nYou entered the area as " << area << " mm^2....\n";
   radsq = area / pi;    // Calculate radius
   cout << radmsg << sqrt(radsq) << " mm\n";
   rad = radsq;
   diam = sqrt(radsq) * 2;  // Calculate diameter
	cout << diamsg << diam << " mm\n";
   circum = 2 * pi * sqrt(radsq);    // Calculate circumference
   cout << cirmsg << circum << " mm\n";
   break;

   	case 5:
      return 0;

}
   
}