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#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;
const double eps = 1e-8;
const int maxp=105;
int (double x){
if(fabs(x)<eps) return 0;
if(x<0) return -1;
else return 1;
}
struct Point{
double x,y;
Point(){}
Point(double _x,double _y){
x = _x;
y = _y;
}
void input(){
scanf("%lf%lf",&x,&y);
}
Point operator - (const Point &b)const{
return Point(x-b.x,y-b.y);
}
double operator ^ (const Point &b)const{
return x*b.y - y*b.x;
}
};
struct Line{
Point s,e;
Line(){}
Line(Point _s,Point _e){
s = _s;
e = _e;
}
void input(){
s.input();
e.input();
}
bool parallel(Line v){
return sgn((e-s)^(v.e-v.s)) == 0;
}
Point crosspoint(Line v){
double a1 = (v.e-v.s)^(s-v.s);
double a2 = (v.e-v.s)^(e-v.s);
return Point((s.x*a2-e.x*a1)/(a2-a1),(s.y*a2-e.y*a1)/(a2-a1));
}
};
struct polygon {
int n;
Point p[maxp];
Line l[maxp];
void getline() {
for(int i=0;i<n;++i)
l[i] = Line(p[i],p[(i+1)%n]);
}
void input(int _n) {
n = _n;
for (int i=0;i<n;i++)
p[i].input();
}
};
struct halfplane:public Line{
double angle;
halfplane(){}
halfplane(Point _s,Point _e){
s = _s;
e = _e;
}
halfplane(Line v){
s = v.s;
e = v.e;
}
void calcangle(){
angle = atan2(e.y-s.y,e.x-s.x);
}
bool operator <(const halfplane &b)const{
return angle < b.angle;
}
};
struct halfplanes{
int n;
halfplane hp[maxp];
Point p[maxp];
int que[maxp];
int st,ed;
void push(halfplane tmp){
hp[n++] = tmp;
}
void unique(){
int m = 1;
for (int i = 1;i < n;i++)
{
if(sgn(hp[i].angle-hp[i-1].angle)!=0)
hp[m++] = hp[i];
else if(sgn((hp[m-1].e-hp[m-1].s) ^ (hp[i].s-hp[m-1].s)) > 0)
hp[m-1] = hp[i];
}
n = m;
}
bool halfplaneinsert(){
for (int i=0; i < n;i++)
hp[i].calcangle();
sort(hp,hp+n);
unique();
que[st=0] = 0;
que[ed=1] = 1;
p[1] = hp[0].crosspoint(hp[1]);
for (int i=2;i<n;i++)
{
while (st<ed && sgn((hp[i].e-hp[i].s) ^(p[ed]-hp[i].s))<0 )
ed--;
while (st<ed && sgn((hp[i].e-hp[i].s)^(p[st+1]-hp[i].s))<0)
st++;
que[++ed]=i;
if(hp[i].parallel(hp[que[ed-1]]))
return false;
p[ed]=hp[i].crosspoint(hp[que[ed-1]]);
}
while (st<ed && sgn((hp[que[st]].e-hp[que[st]].s) ^(p[ed]-hp[que[st]].s))<0 )
ed--;
while (st<ed && sgn((hp[que[ed]].e-hp[que[ed]].s)^(p[st+1]-hp[que[ed]].s))<0)
st++;
if(st+1 >=ed) return false;
return true;
}
};
int main()
{
int T;
scanf("%d",&T);
while (T--)
{
int n;
scanf("%d",&n);
halfplanes A;
polygon pol;
pol.input(n);
pol.getline();
A.n=0;
for (int i=0;i<n;i++)
{
Line line = pol.l[i];
swap(line.s,line.e);
A.push(halfplane(line));
}
if(A.halfplaneinsert())
puts("YES");
else puts("NO");
}
return 0;
}
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