#include <bits/stdc++.h>
using namespace std;
int t, n;
int xa[10020];
int xb[10020];
int ya[10020];
int yb[10020];
int xs, ys, xe, ye;
int xx[100020], xc;
int yy[100020], yc;
int ax[420][420];
int ay[420][420];
vector<pair<int, double> > a[200020];
double d[200020];
int main() {
    scanf("%d", &t);
    for (int tt = 0; tt < t; tt++) {
        scanf("%d", &n);
        xc = yc = 0;
        memset(ax, 0, sizeof ax);
        memset(ay, 0, sizeof ay);
        for (int i = 0; i < n; i++) {
            scanf("%d%d%d%d", &xa[i], &ya[i], &xb[i], &yb[i]);
            xx[xc++] = xa[i];
            xx[xc++] = xb[i];
            yy[yc++] = ya[i];
            yy[yc++] = yb[i];
        }
        scanf("%d%d%d%d", &xs, &ys, &xe, &ye);
        // printf("%d %d %d %d\n", xs, ys, xe, ye);
        xx[xc++] = xs;
        xx[xc++] = xe;
        yy[yc++] = ys;
        yy[yc++] = ye;
        sort(xx, xx + xc);
        sort(yy, yy + yc);
        xc = unique(xx, xx + xc) - xx;
        yc = unique(yy, yy + yc) - yy;
        for (int i = 0; i < xc * yc; i++) {
            a[i].clear();
        }
        for (int i = 0; i < n; i++) {
            xa[i] = lower_bound(xx, xx + xc, xa[i]) - xx;
            xb[i] = lower_bound(xx, xx + xc, xb[i]) - xx;
            ya[i] = lower_bound(yy, yy + yc, ya[i]) - yy;
            yb[i] = lower_bound(yy, yy + yc, yb[i]) - yy;
        }
        xs = lower_bound(xx, xx + xc, xs) - xx;
        xe = lower_bound(xx, xx + xc, xe) - xx;
        ys = lower_bound(yy, yy + yc, ys) - yy;
        ye = lower_bound(yy, yy + yc, ye) - yy;
        // printf("%d %d %d %d\n", xs, ys, xe, ye);
        for (int i = 0; i < n; i++) {
            for (int j = xa[i]; j < xb[i]; j++) {
                for (int k = ya[i]; k <= yb[i]; k++) {
                    ax[j][k]++;
                }
            }
            for (int j = xa[i]; j <= xb[i]; j++) {
                for (int k = ya[i]; k < yb[i]; k++) {
                    ay[j][k]++;
                }
            }
        }
        for (int i = 0; i < xc; i++) {
            for (int j = 0; j < yc - 1; j++) {
                a[i * yc + j].push_back(make_pair(i * yc + j + 1, (yy[j + 1] - yy[j]) / (ay[i][j] + 1.0)));
                a[i * yc + j + 1].push_back(make_pair(i * yc + j, (yy[j + 1] - yy[j]) / (ay[i][j] + 1.0)));
                // printf("%d %d %.6f\n", i * yc + j, i * yc + j + 1, (yy[j + 1] - yy[j]) / (ay[i][j] + 1.0));
            }
        }
        for (int i = 0; i < xc - 1; i++) {
            for (int j = 0; j < yc; j++) {
                a[i * yc + j].push_back(make_pair(i * yc + j + yc, (xx[i + 1] - xx[i]) / (ax[i][j] + 1.0)));
                a[i * yc + j + yc].push_back(make_pair(i * yc + j, (xx[i + 1] - xx[i]) / (ax[i][j] + 1.0)));
                // printf("%d %d %.6f\n", i * yc + j, i * yc + j + yc, (xx[i + 1] - xx[i]) / (ax[i][j] + 1.0));
            }
        }
        for (int i = 0; i < xc * yc; i++) {
            d[i] = 1e30;
        }
        priority_queue<pair<double, int> > q;
        d[xs * yc + ys] = 0;
        q.push(make_pair(-d[xs * yc + ys], xs * yc + ys));
        while (q.size() > 0) {
            pair<double, int> u = q.top();
            q.pop();
            if (-u.first > d[u.second]) {
                continue;
            }
//            printf("%.6f %d\n", u.first, u.second, d[u.second]);
            for (int i = 0; i < a[u.second].size(); i++) {
                pair<int, double> e = a[u.second][i];
                if (d[e.first] > d[u.second] + e.second) {
//                    printf("%.6f %.6f %.6f\n", d[e.first], d[u.second] + e.second, e.second);
                    d[e.first] = d[u.second] + e.second;
                    q.push(make_pair(-d[e.first], e.first));
                }
            }
        }
        // printf("%d %d %d %d\n", xs, ys, xe, ye);
        printf("%.5f\n", d[xe * yc + ye]);
    }
    return 0;
}