/*
 * third.c
 */
#include <stdio.h>
#include <math.h>
int main() {
    double radius, area ;

    printf("Enter the radius: "); 
    scanf("%lf", &radius) ;
    area = M_PI*radius*radius ;
    printf("Circle-Area = %lf for Radius = %lf\n",
                           area, radius); 
    return 0 ;
} // Area of a circle third.c