#define LOCAL

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef double D;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef pair<int,int> PII;
typedef pair<ll,ll> PLL;

#define rd(x) scanf("%d",&x)
#define rd2(x,y) scanf("%d %d",&x,&y)
#define rl(x) scanf("%lld",&x)
#define rl2(x,y) scanf("%lld %lld",&x,&y)
#define wd(x) printf("%d" ,x)
#define wd2(x,y) printf("%d %d",x,y)
#define wl(x) printf("%lld",x)
#define wl2(x,y) printf("%lld %lld",x,y)
#define PC(x) putchar(x)
#define GC() getchar()
#define NL printf("\n")
#define SP printf(" ")

#define F first
#define S second
#define MP make_pair
#define PB push_back

#define fr(i,s,e) for(int i=s;i<e;i++)
#define frr(i,s,e) for(int i=s-1;i>=e;i--)
#define frv(i,a) for(int i = 0;i<(int)a.size();i++)
#define frvr(i,a) for(int i = a.size()-1;i>=0;i--)
#define tr(i,a) for(typeof(a.begin()) i = a.begin(); i != a.end();i++)

#ifdef LOCAL
#define E1(a) cout<<#a<<":" <<a<<endl;
#define E2(a,b) cout<<#a<<":" <<a<<" " <<#b<<":" <<b<<endl;
#define E3(a,b,c) cout<<#a<<":" <<a<<" " <<#b<<":" <<b<<" "<<#c<<":"<<c<<endl;
#define E4(a,b,c,d) cout<<#a<<":" <<a<<" " <<#b<<":" <<b<<" "<<#c<<":"<<c<< " "<<#d<< ":"<<d<<endl;
#define INP freopen("input","r",stdin);
#define OUT freopen("output","w",stdout);
#else
#define E1(a)
#define E2(a,b)
#define E3(a,b,c)
#define E4(a,b,c,d)
#define INP
#define OUT
#endif

#define mod 1000000007
#define maxn 100009
#define maxr 100009



int x[maxn],y[maxn];
ll d[maxn];
set<PII> st;


bool b;








int main(){

	int t;
	t = 1;
	rd(t);
	while(t--){
		b  = 0;

		int n;
		rd(n);
		fr(i,0,n){
			int a,b;
			rd2(a,b);
			st.insert(MP(a,b));
		}

		if(int(st.size()<=4))b = 1;
		else{
			n = 0;
			for(set<PII>::iterator it = st.begin();it!=st.end();it++){
				x[n] = it->F;
				x[n] = it->S;
				n++;
			}

			fr(i,0,n){
				fr(j,i+1,n){

					ll a,b,c;
					a = y[i]-y[j];
					b = x[j]-x[i];
					c = y[j]*(x[i]-x[j]) + x[j]*(y[j]-y[i]);


					bool b1,b2;
					b1 = b2 = 0;

					ll mx = 0;

					fr(k,0,n){
						d[k] = a*x[k]+b*y[k] + c;
						if(d[k]>0){b1 = 1;}
						else if(d[k]<0){b2 = 1;}
						mx = max(mx,d[k]);
					}

					if(b1&&b2)continue;

					vector<PII> v1,v2;

					fr(k,0,n){
						if(d[k]==0||d[k]==mx)continue;

						if(v1.empty()){v1.PB(MP(x[k],y[k]));continue;}
						else{
							PII pr = v1.back();
							ll aa = pr.F-x[k];
							ll bb = pr.S-y[k];
							if(b*bb==a*aa){v1.PB(MP(x[k],y[k]));continue;}
						}
						if(v2.empty()){v2.PB(MP(x[k],y[k]));continue;}
						else{
							PII pr = v2.back();
							ll aa = pr.F-x[k];
							ll bb = pr.S-y[k];
							if(b*bb==a*aa){v2.PB(MP(x[k],y[k]));continue;}
						}
						break;
					}
				}
			}
		}



		if(b)cout<<"YES"<<endl;
		else cout<<"NO"<<endl;


	}
}