/*--------------------------------------------------
created by st10 at Fri Oct 14 12:06:08 PDT 2016
--------------------------------------------------*/
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include "circ_area.h"
using namespace std;


/*--------------------------------------------------
 signature: circ_area : double -> double
 purpose: expects a circle's radius and returns that circle's
    area

 examples: circ_area(1) == 3.14159
           circ_area(10) == 314.159
--------------------------------------------------*/

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