#include <stdio.h>
#define PI 3.1415926536

int main(void)
{
//  Local Declarations
    const double cPi = PI;
    float radius_circle, area_circle;
 
//  Statements
    printf("Please enter the radius of the circle:", radius_circle);
    scanf("%f", &radius_circle);
    area_circle = PI * radius_circle * radius_circle;
    printf("The area of the circle is:  %.2f\a\n", area_circle);
    printf("Thank you!!!\n");
   
    system("pause");
    return 0;
}// main