OJ Board

well.. thank you for your answer
and i have tried your advice
but i still got WA
this is my program and may be you can tell me why i got WA :D

...

int main()
{
while (!feof(stdin)) {
fscanf(stdin,"%f %f %f %f %f %f",&x[0],&y[0],&x[1],&y[1],&x[2],&y[2]);
hitung();
output();
printf("\n\n ...