#include<bits/stdc++.h>
using namespace std;
#define eps 0.00000000001
#define ll long long int
#define pii pair<int,int>
#define pll pair<ll,ll>
#define vi vector<int>
#define pb push_back
#define mp make_pair
#define fr first
#define se second
#define MOD 1000000007

double slope(pii v  , pii u) {
    if (fabs((double)v.first - u.first) < eps)
        return 99999999999999;
    return  ((double)(v.second - u.second)) / ((double)v.first - u.first) ;
}

int main ()
{
	//freopen("input.txt","r",stdin);
	ios_base::sync_with_stdio(false);
    int t;
    cin >> t;
    while(t--) {

        int n ;
        cin >> n;
        vector<pair<int, int > > v;
        //v.resize(n);
        for(int i = 0; i < n; i++) {
            int x,y;
            cin>>x>>y;
            v.pb(mp(x,y));
        }
        int answer = 0;
        double slope_vertical , slope_horizontal;
        for(int i = 0; i < n; i++) {
            for(int j = i+1; j < n; j++) {
                for(int k = j+1; k < n; k++) {
                    bool flag = true;
                    //cout << ((double)v[i].first - v[k].first) << endl;
                    if(fabs((double)v[i].first - v[j].first) < eps) {
                        slope_horizontal = 99999999999999;
                    } else {
                        slope_horizontal =  ((double)(v[i].second - v[j].second)) / ((double)v[i].first - v[j].first) ;
                    }

                    if(fabs((double)v[i].first - v[k].first) < eps) {
                        slope_vertical = 99999999999999;
                    } else {
                         slope_vertical = ((double)(v[i].second - v[k].second)) / ((double)v[i].first - v[k].first) ;
                    }


                    for(int l = 0; l < n; l++) {


                            if( l != i && l != j && l != k ) {
                                    //cerr << l << " "  << i << j << k << endl;
                                    //cout << slope_horizontal <<"  "<<slope_vertical<<"   "<<slope( v[i], v[l]) <<"  "<<slope( v[i], v[l])<<endl;

                                if( fabs(slope( v[i], v[l]) - slope_horizontal) < eps || fabs(slope( v[i], v[l]) - slope_vertical) < eps ) {
                                    //cout<<"*"<<endl;


                                } else if( fabs(slope( v[j], v[l]) - slope_horizontal) < eps || fabs(slope( v[j], v[l]) - slope_vertical) < eps) {
                                    //cout<<"**"<<endl;

                                } else if(fabs(slope( v[k], v[l]) - slope_horizontal) < eps || fabs(slope( v[k], v[l]) - slope_vertical) < eps ) {
//cout<<"***"<<endl;

                                } else {
                                    flag = false;
                                }
                            }
                    }
                    if( flag) {
                        answer = 1;
                    }
                }
            }
        }

        if( answer ) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }

    }

	return 0;
}