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

const int N = 510;
typedef double ld;
const int inf = 2000000001;
struct element{
    int id;
    ld weight;
};
struct cmp{
    bool operator () (element x, element y){
        return x.weight > y.weight;
    }
};
priority_queue<element, vector<element>, cmp> hp;

struct edge{
    int ne, to;
    ld w;
}e[2000100];
int he[N * N], tot = 0, n, m, S, T, vis[N * N], binx[N], biny[N], cntx, cnty;
ld dis[N * N];

struct rectangle{
    int x1, x2, y1, y2;
}rec[N];

void add(int x, int y, ld w){
    e[++tot].ne = he[x];
    he[x] = tot;
    e[tot].to = y;
    e[tot].w = w;
}

void addedge(int x, int y, ld w){
    add(x, y, w);
    add(y, x, w);
}

int sort_and_unique(int array[], int &n){
    sort(array + 1, array + n + 1);
    int top = 0, i, j;
    for (i = 1; i <= n; i = j + 1){
        j = i;
        while ((j < n) && (array[j + 1] == array[j])){
            j++;
        }
        array[++top] = array[i];
    }
    n = top;
}

void dijkstra(){
    int i, j, x, y;
    while (!hp.empty()){
        hp.pop();
    }
    for (i = 1; i <= m; i++){
        dis[i] = inf;
        vis[i] = 0;
    }
    dis[S] = 0;
    hp.push((element){S, 0});
    while (!hp.empty()){
        x = hp.top().id;
        hp.pop();
        if (vis[x]){
            continue;
        }
        vis[x] = 1;
        for (i = he[x]; i; i = e[i].ne){
            y = e[i].to;
            if (dis[y] > dis[x] + e[i].w){
                dis[y] = dis[x] + e[i].w;
                hp.push((element){y, dis[y]});
            }
        }
    }
}

void init(){
    memset(he, 0, sizeof(he));
    tot = 0;
}

int main(){
    //freopen("a.in", "r", stdin);
    //freopen("b.out", "w", stdout);
    int i, j, k, Ti;
    int stx, sty, edx, edy;
    scanf("%d", &Ti);
    while (Ti--){
        init();
        scanf("%d", &n);
        cntx = 0;
        cnty = 0;
        for (i = 1; i <= n; i++){
            scanf("%d%d%d%d", &rec[i].x1, &rec[i].y1, &rec[i].x2, &rec[i].y2);
            binx[++cntx] = rec[i].x1;
            binx[++cntx] = rec[i].x2;
            biny[++cnty] = rec[i].y1;
            biny[++cnty] = rec[i].y2;
        }

        binx[++cntx] = 0;
        binx[++cntx] = 1000000000;
        biny[++cnty] = 0;
        biny[++cnty] = 1000000000;
        scanf("%d%d%d%d", &stx, &sty, &edx, &edy);
        binx[++cntx] = stx;
        binx[++cntx] = edx;
        biny[++cnty] = sty;
        biny[++cnty] = edy;

        sort_and_unique(binx, cntx);
        sort_and_unique(biny, cnty);

        m = cntx * cnty;
        for (i = 1; i <= cntx; i++){
            for (j = 1; j <= cnty; j++){
                if ((stx == binx[i]) && (sty == biny[j])){
                    S = (i - 1) * cnty + j;
                }
                if ((edx == binx[i]) && (edy == biny[j])){
                    T = (i - 1) * cnty + j;
                }
                if (j == cnty){
                    continue;
                }
                int pass_cnt = 1;
                for (k = 1; k <= n; k++){
                    if ((rec[k].x1 <= binx[i]) && (binx[i] <= rec[k].x2) && (biny[j] >= rec[k].y1) && (biny[j + 1] <= rec[k].y2)){
                        pass_cnt++;
                    }
                }
                int cur = (i - 1) * cnty + j;
                addedge(cur, cur + 1, (ld)(biny[j + 1] - biny[j]) / (ld)pass_cnt);
            }
        }

        for (i = 1; i < cntx; i++){
            for (j = 1; j <= cnty; j++){
                int pass_cnt = 1;
                for (k = 1; k <= n; k++){
                    if ((rec[k].x1 <= binx[i]) && (binx[i + 1] <= rec[k].x2) && (biny[j] >= rec[k].y1) && (biny[j] <= rec[k].y2)){
                        pass_cnt++;
                    }
                }
                int cur = (i - 1) * cnty + j;
                addedge(cur, cur + cnty, (ld)(binx[i + 1] - binx[i]) / (ld)pass_cnt);
            }
        }
        dijkstra();
        printf("%.5f\n", dis[T] + 1e-9);
    }
    return 0;
}