#include <stdio.h>
#include <math.h>
int main()
{
int i=1;
int a,b,c;
scanf("%d%d%d",&a,&b,&c);
while((a!=0)&&(b!=0)&&(c!=0))
{
if(a==-1)
{
if((c*c-b*b)>0&&c>0&&b>0)
{
printf("Triangle #%d\na = %.3f\n\n",i,(double)sqrt(c*c-b*b));
}
else
{
printf("Triangle #%d\nImpossible.\n\n",i);
}
}
if(b==-1)
{
if((c*c-a*a)>0&&c>0&&a>0)
{
printf("Triangle #%d\nb = %.3f\n\n",i,(double)sqrt(c*c-a*a));
}
else
{
printf("Triangle #%d\nImpossible.\n\n",i);
}
}
if(c==-1)
{
if(a>0&&b>0)
{
printf("Triangle #%d\nc = %.3f\n\n",i,(double)sqrt(a*a+b*b));
}
else
{
printf("Triangle #%d\nImpossible.\n\n",i);
}
}
scanf("%d%d%d",&a,&b,&c);
i++;
}
return 0;
}