zad4

#include <stdio.h>
#include <math.h>

int main()
{
   float a, b, c, P, p, S;
   printf("a = ");
   scanf("%f", &a);
   printf("b = ");
   scanf("%f", &b);
   printf("c = ");
   scanf("%f", &c);
    P = a + b + c;
    p = (a + b + c)/2;
    S = sqrt(p*(p-a)*(p-b)*(p-c));
   if(a > 0 && b > 0 && c > 0 && a + b > c && a + c > b && b + c > a)
   {
    printf("P = %.2f\n", P);
    printf("S = %.2f\n", S);
   }
   else //if (a < 0 || b < 0 || c < 0 || a + b < c || a + c < b || b + c < a)
   {
    printf("Error");
   }
   if(a == b || b == c ||c == a)
   {
       printf("Triangle is isosceles\n");
   }
   if(a == b && b == c && c == a)
   {
       printf("Triangle is equilateral");
   }
   if()
   {

   }
   return 0;
}