/* Note:Your choice is C IDE */
#include "stdio.h"
#include "math.h"
main()
{   float a,b,c,s,area;
    printf("enter a,b,c\n");
    scanf("%f,%f,%f",&a,&b,&c);
    if(a+b>c&&a+c>b&&b+c>a);
      {   s=(a+b+c)/2;
            area=sqrt(s*(s-a)*(s-b)*(s-c));
            printf("a=%7.2f,b=%7.2f,c=%7.2f\n",a,b,c);
            printf("area=%7.2f\n",area);
      }
      else
      {   printf("a=%7.2f,b=%7.2f,c=%7.2f\n",a,b,c);
            printf("input data error");
      }      
}