2i
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main () {
   double a,b,c;
   scanf ("%lf%lf%lf" ,&a, &b, &c);
   if ((a<=0) || (b<=0) || (c<=0) || (a+b <= c) || (a+c <= b) || (b+c <= a))
   {
      printf ("Not a triangle\n"); //не треугольник//
   }
      else if ((a==b) && (a==c) && (b==c))
   {
      printf ( "Equilateral triangle\n"); //равносторонний//
   }
      else if ((a==b) || (a==c) || (b==c))
      {
         printf ( "Isosceles triangle\n"); //равнобедренный//
      }
      else
         {
            printf ( "Scalene triangle\n"); //разносторонний//
         }
         return 0;
}

2K

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main ()
{ double a,b,c,d;
   scanf ("%lf%lf%lf%lf" ,&a, &b, &c, &d);
   if ((a<=c) & (b<=d))
   {
      printf ("Yes\n");
   }
else
   if ((a<=d) & (b<=c))
   {
      printf ("Yes\n");
   }
  else
          printf ("No\n");
return 0; }

2L
 #include <stdio.h>
 #include <stdlib.h>
 int main ()
 {
    double a,b,c,x,y;
    scanf ("%lf%lf%lf" ,&a, &b, &c);
    scanf ("%lf%lf" ,&x, &y);
       if ((a<=x) && (b<=y))
       {
printf ("Yes\n");
       }
else
          if ((a<=x) && (c<=y))
       {
printf ("Yes\n");
       }
else
       if ((b<=x) && (c<=y))
       {
printf ("Yes\n");
       }
else
       if ((a<=y) && (b<=x))
       {
printf ("Yes\n");
       }
else
          if ((a<=y) && (c<=x))
       {
printf ("Yes\n");
       }
else
       if ((b<=y) && (c<=x))
       {
printf ("Yes\n");
       }
       else
          printf ("No\n");
 return 0; }