#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int main (void)
{
int n;
double x1,x2,x3,y1,y2,y3;
double a,b,c,p,s;
int i;
do{
if(scanf("%d",&n)!=1)break;
for(i=0;i<n;i++){
scanf("%lf %lf %lf %lf %lf %lf",&x1,&y1,&x2,&y2,&x3,&y3);
}
a=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
b=sqrt((x2-x3)*(x2-x3)+(y2-y3)*(y2-y3));
c=sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1));
p=(a+b+c)/2;
s=sqrt(p*(p-a)*(p-b)*(p-c));
if(s>0)
printf("YES");
else
printf("NO");
//printf("(%.0lf,%.0lf),(%.0lf,%.0lf),(%.0lf,%.0lf)",x1,y1,x2,y2,x3,y3);
}while(1);
return 0;
}