/*--------------------------------------------------
created by st10 at Mon Mar  8 13:38:09 PST 2010
--------------------------------------------------*/
#include <iostream>
#include <cmath>
#include "circ_area.h"
using namespace std;


/*--------------------------------------------------
 Contract: circ_area : double -> double
 Purpose: 
    expects a circle's radius, and produces the
    area of that circle

 Examples: abs( circ_area(10) - 314.159 ) < 0.001
          circ_area(10) == 314.159
--------------------------------------------------*/

double circ_area(double radius)
{
    return PI * radius * radius;
}