// File name: circle.cpp
// Author: Xiannong Meng
// Course: CS2330
// Date: January 15, 1997
// Assignment: classroom demonstration
// Problem statement: This program calcualtes radius and circumference
//   of a circle for a given area value, using math. functions.

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

void main(void)
{
   // constants
   const float PI = 3.14159;
   
   // variables
   float area;       // input: area of circle
   float radius;     // output: radius of circle
   float circum;     // output: circumference of circle

   // read input
   cout << "Enter the area of the circle : ";
   cin >> area;

   // calcualte circle radius, using math function 'sqrt'
   radius = sqrt( area / PI );
   
   // calcualte circle circumference
   circum = 2 * PI * radius;

   // display the result
   cout << "The radius of the circle is " << radius << endl;
   cout << "The circumference of the circle is " << circum << endl;
}