#include "stdio.h"
#include "math.h"
void main()
{
float a,b,c,s,area,perimeter;
printf("請輸入三角形的三邊:");
scanf("%f,%f,%f",&a,&b,&c);
s=1.0/2*(a+b+c);
area=sqrt(s*(s-a)*(s-b)*(s-c));
perimeter=a+b+c;
if(a+b>c||a-b<c)
printf("%5.2f,%5.2f\n",area,perimeter);
else
printf("These sides do not correspond to a valid triangle");
}