#include<bits/stdc++.h>
#define N 405
#define y1 Y1
using namespace std;
int x1[N],y1[N],x2[N],y2[N],X[N],Y[N];
int num[N][N],n,xa,ya,xb,yb,st,ed;
vector<pair<int,double> >a[N*N];
set<pair<double,int> >G;double f[N*N];
double DIJ(int n){
    for (int i=1;i<=n;i++) f[i]=1e100;
    f[st]=0;G.clear();
    G.insert(make_pair(f[st],st));
    while (!G.empty()){
        pair<double,int>tmp=*G.begin();G.erase(G.begin());
        int x=tmp.second;if (f[x]<tmp.first) continue;
        if (x==ed) return f[ed];
        for (int i=0;i<a[x].size();i++){
            int y=a[x][i].first;
            if (f[x]+a[x][i].second<f[y])
                G.insert(make_pair(f[y]=f[x]+a[x][i].second,y));
        }
    }
    assert(0);
}
void add(int x,int y,double z){
    a[x].push_back(make_pair(y,z));
    //printf("%d %d %.6f\n",x,y,z);
}
int main(){
    int T;scanf("%d",&T);
    while (T--){
        scanf("%d",&n);
        *X=*Y=0;
        for (int i=1;i<=n;i++){
            scanf("%d%d%d%d",&x1[i],&y1[i],&x2[i],&y2[i]);
            X[++*X]=x1[i];X[++*X]=x2[i];
            Y[++*Y]=y1[i];Y[++*Y]=y2[i];
        }
        
        scanf("%d%d%d%d",&xa,&ya,&xb,&yb);
        X[++*X]=xa;X[++*X]=xb;Y[++*Y]=ya;Y[++*Y]=yb;
        sort(X+1,X+*X+1);*X=unique(X+1,X+*X+1)-(X+1);
        sort(Y+1,Y+*Y+1);*Y=unique(Y+1,Y+*Y+1)-(Y+1);
        
        int tot=0;
        for (int i=1;i<=*X;i++)
            for (int j=1;j<=*Y;j++)
                num[i][j]=++tot;
        for (int i=1;i<=*X;i++)
            for (int j=1;j<=*Y;j++){
                int A=1,B=1,C=1,D=1;
                for (int k=1;k<=n;k++){
                    A+=x1[k]<=X[i-1]&&X[i]<=x2[k]&&y1[k]<=Y[j]&&Y[j]<=y2[k];
                    B+=x1[k]<=X[i]&&X[i+1]<=x2[k]&&y1[k]<=Y[j]&&Y[j]<=y2[k];
                    C+=x1[k]<=X[i]&&X[i]<=x2[k]&&y1[k]<=Y[j-1]&&Y[j]<=y2[k];
                    D+=x1[k]<=X[i]&&X[i]<=x2[k]&&y1[k]<=Y[j]&&Y[j+1]<=y2[k];
                }
                if (i>1) add(num[i][j],num[i-1][j],(X[i]-X[i-1])*1.0/A);
                if (i<*X) add(num[i][j],num[i+1][j],(X[i+1]-X[i])*1.0/B);
                if (j>1) add(num[i][j],num[i][j-1],(Y[j]-Y[j-1])*1.0/C);
                if (j<*Y) add(num[i][j],num[i][j+1],(Y[j+1]-Y[j])*1.0/D);
            }
        for (int i=1;i<=*X;i++)
            for (int j=1;j<=*Y;j++){
                if (X[i]==xa&&Y[j]==ya) st=num[i][j];
                if (X[i]==xb&&Y[j]==yb) ed=num[i][j];
            }
        printf("%.5f\n",DIJ(tot));
        for (int i=1;i<=tot;i++) a[i].clear();
    }
}