#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    int q, n;
    int x[10];
    int y[10];
    cin >> q;
    while (q--) {
        cin >> n;
        int maxx = -10001, maxy = -10001, minx = 10001, miny = 10001;
        for (int i = 0; i < n; i++) {
            cin >> x[i] >> y[i];
            if (x[i] > maxx) maxx = x[i];
            if (x[i] < minx) minx = x[i];
            if (y[i] > maxy) maxy = y[i];
            if (y[i] < miny) miny = y[i];
        }
        if (n < 4) {
            cout << "YES\n";
        } else if (n == 4) {
            bool yes = true;
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    if (i == j) continue;
                    for (int k = 0; k < n; k++) {
                        if (i == k || j == k) continue;
                        if ((y[k] - y[j]) * (x[k] - x[j]) == (y[k] - y[i]) * (x[k] - x[i])) {
                            yes = false;
                            j = n;
                            i = n;
                            break;
                        }
                    }
                }
            }
            if (yes) cout << "YES\n";
            else cout << "NO\n";
        } else {
            int cornerx[4] = {-10001, -10001, 10001, 10001}, cornery[4] = {-10001, 10001, -10001, 10001};
            for (int i = 0; i < n; i++) {
                if (x[i] > cornerx[0] && y[i] > cornerx[0]) {
                    cornerx[0] = x[i];
                    cornery[0] = y[i];
                }
                if (x[i] > cornerx[1] && y[i] < cornery[1]) {
                    cornerx[1] = x[i];
                    cornery[1] = y[i];
                }
                if (x[i] < cornerx[2] && y[i] > cornery[2]) {
                    cornerx[2] = x[i];
                    cornery[2] = y[i];
                }
                if (x[i] < cornerx[3] && y[i] < cornery[3]) {
                    cornerx[3] = x[i];
                    cornery[3] = y[i];
                }
            }
            bool yes = true;
            for (int i = 0; i < n; i++) {
                bool cornerside = false;
                if (abs(cornery[0] - cornery[1]) * (cornerx[0] - cornerx[1]) == abs((cornery[0] - y[i]) * (cornerx[0] - x[i]))) {
                    cornerside = true;
                    continue;
                }
                if (abs(cornery[1] - cornery[3]) * (cornerx[1] - cornerx[3]) == abs((cornery[1] - y[i]) * (cornerx[1] - x[i]))) {
                    cornerside = true;
                    continue;
                }
                if (abs(cornery[3] - cornery[2]) * (cornerx[3] - cornerx[2]) == abs((cornery[2] - y[i]) * (cornerx[2] - x[i]))) {
                    cornerside = true;
                    continue;
                }
                if (abs(cornery[3] - cornery[0]) * (cornerx[2] - cornerx[0]) == abs((cornery[2] - y[i]) * (cornerx[2] - x[i]))) {
                    cornerside = true;
                    continue;
                }
                yes = false;
                break;
            }
            if (yes) cout << "YES\n";
            else cout << "NO\n";
        }
    }
    return 0;
}