#include <cstdio>
#include <algorithm>
#include <queue>

#define mp std::make_pair
typedef long long LL;
typedef std::pair<double, int> pdi;
const int MN = 405;

int N, sx[MN], sy[MN], tx[MN], ty[MN];
int Sx, Sy, Tx, Ty;
int dx[MN], dy[MN], cx, cy;
int c[MN][MN];

inline int id(int x, int y) { return (x - 1) * cy + y; }

int h[MN * MN], nxt[MN * MN * 4], to[MN * MN * 4], tot;
double w[MN * MN * 4];
inline void insw(int x, int y, double z) {
    nxt[++tot] = h[x], to[tot] = y, w[tot] = z, h[x] = tot;
    nxt[++tot] = h[y], to[tot] = x, w[tot] = z, h[y] = tot;
}

int vis[MN * MN];
double dis[MN * MN];
std::priority_queue<pdi, std::vector<pdi>, std::greater<pdi> > pq;

int main() {
    int T; scanf("%d", &T);
    while (T--) {
        scanf("%d", &N), tot = cx = cy = 0;
        for (int i = 1; i <= N; ++i) {
            scanf("%d%d%d%d", &sx[i], &sy[i], &tx[i], &ty[i]);
            dx[++cx] = sx[i], dy[++cy] = sy[i];
            dx[++cx] = tx[i], dy[++cy] = ty[i];
        }
        scanf("%d%d%d%d", &Sx, &Sy, &Tx, &Ty);
        dx[++cx] = Sx, dy[++cy] = Sy;
        dx[++cx] = Tx, dy[++cy] = Ty;
        std::sort(dx + 1, dx + cx + 1), cx = std::unique(dx + 1, dx + cx + 1) - dx - 1;
        std::sort(dy + 1, dy + cy + 1), cy = std::unique(dy + 1, dy + cy + 1) - dy - 1;
        for (int j = 1; j <= cx; ++j)
            for (int k = 1; k <= cy; ++k) {
                int i = id(j, k);
                c[j][k] = 1, h[i] = 0, dis[i] = 1e99, vis[i] = 0;
            }
        for (int i = 1; i <= N; ++i) {
            sx[i] = std::lower_bound(dx + 1, dx + cx + 1, sx[i]) - dx;
            sy[i] = std::lower_bound(dy + 1, dy + cy + 1, sy[i]) - dy;
            tx[i] = std::lower_bound(dx + 1, dx + cx + 1, tx[i]) - dx;
            ty[i] = std::lower_bound(dy + 1, dy + cy + 1, ty[i]) - dy;
            for (int j = sx[i]; j < tx[i]; ++j)
                for (int k = sy[i]; k < ty[i]; ++k)
                    ++c[j][k];
        }
        Sx = std::lower_bound(dx + 1, dx + cx + 1, Sx) - dx;
        Sy = std::lower_bound(dy + 1, dy + cy + 1, Sy) - dy;
        Tx = std::lower_bound(dx + 1, dx + cx + 1, Tx) - dx;
        Ty = std::lower_bound(dy + 1, dy + cy + 1, Ty) - dy;
        for (int j = 1; j <= cx; ++j)
            for (int k = 1; k < cy; ++k)
                insw(id(j, k), id(j, k + 1), (double)(dy[k + 1] - dy[k]) / std::max(c[j - 1][k], c[j][k]));
        for (int k = 1; k <= cy; ++k)
            for (int j = 1; j < cx; ++j)
                insw(id(j, k), id(j + 1, k), (double)(dx[j + 1] - dx[j]) / std::max(c[j][k - 1], c[j][k]));
        int S = id(Sx, Sy), T = id(Tx, Ty);
        dis[S] = 0., pq.push(mp(0., S));
        while (!pq.empty()) {
            pdi p = pq.top(); pq.pop();
            int u = p.second; double d = p.first;
            if (vis[u]) continue;
            vis[u] = 1;
            for (int i = h[u]; i; i = nxt[i]) {
                if (dis[to[i]] > d + w[i]) {
                    dis[to[i]] = d + w[i];
                    pq.push(mp(dis[to[i]], to[i]));
                }
            }
        }
        printf("%.5lf\n", dis[T]);
    }
    return 0;
}