#include<bits/stdc++.h>
using namespace std;
#define MAXN 200005
#define MAXM 800005
#define real long double
real w[MAXM],d[MAXN];
int T,n,m,i,j,u,v,ax,bx,ay,by,lx[205],rx[205],ly[205],ry[205],N,M,x[405],y[405],a[405][405],b[405][405],h[MAXN],ne[MAXM],p[MAXM];
void add(int x,int y,real z)
{
    p[++m]=y;
    ne[m]=h[x];
    w[m]=z;
    h[x]=m;
    p[++m]=x;
    ne[m]=h[y];
    w[m]=z;
    h[y]=m;
}
struct node
{
    int i;
    real d;
    bool operator<(const node& y)const
    {
        return d>y.d;
    }
}t,t1;
priority_queue<node> H;
int main()
{
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d",&n);
        N=M=0;
        for(i=1;i<=n;i++)
        {
            scanf("%d%d%d%d",lx+i,ly+i,rx+i,ry+i);
            x[++N]=lx[i];
            x[++N]=rx[i];
            y[++M]=ly[i];
            y[++M]=ry[i];
        }
        scanf("%d%d%d%d",&ax,&ay,&bx,&by);
        x[++N]=ax;
        x[++N]=bx;
        y[++M]=ay;
        y[++M]=by;
        sort(x+1,x+N+1);
        sort(y+1,y+M+1);
        N=unique(x+1,x+N+1)-x-1;
        M=unique(y+1,y+M+1)-y-1;
        ax=lower_bound(x+1,x+N+1,ax)-x;
        bx=lower_bound(x+1,x+N+1,bx)-x;
        ay=lower_bound(y+1,y+M+1,ay)-y;
        by=lower_bound(y+1,y+M+1,by)-y;
        memset(a,0,sizeof(a));
        memset(b,0,sizeof(b));
        for(i=1;i<=n;i++)
        {
            lx[i]=lower_bound(x+1,x+N+1,lx[i])-x;
            rx[i]=lower_bound(x+1,x+N+1,rx[i])-x;
            ly[i]=lower_bound(y+1,y+M+1,ly[i])-y;
            ry[i]=lower_bound(y+1,y+M+1,ry[i])-y;
            a[lx[i]][ly[i]]++;
            a[rx[i]][ly[i]]--;
            a[lx[i]][ry[i]+1]--;
            a[rx[i]][ry[i]+1]++;
            b[lx[i]][ly[i]]++;
            b[rx[i]+1][ly[i]]--;
            b[lx[i]][ry[i]]--;
            b[rx[i]+1][ry[i]]++;
        }
        n=N*M;
        m=0;
        fill(h+1,h+n+1,0);
        fill(d+1,d+n+1,1e15);
        for(i=1;i<N;i++)for(j=1;j<=M;j++)
        {
            a[i][j]+=a[i-1][j]+a[i][j-1]-a[i-1][j-1];
            add((i-1)*M+j,i*M+j,(real)(x[i+1]-x[i])/(a[i][j]+1));
        }
        for(i=1;i<=N;i++)for(j=1;j<M;j++)
        {
            b[i][j]+=b[i-1][j]+b[i][j-1]-b[i-1][j-1];
            add((i-1)*M+j,(i-1)*M+j+1,(real)(y[j+1]-y[j])/(b[i][j]+1));
        }
        u=(ax-1)*M+ay;
        v=(bx-1)*M+by;
        d[u]=0;
        t.i=u;
        t.d=0;
        H.push(t);
        while(!H.empty())
        {
            t=H.top();
            H.pop();
            if(d[t.i]!=t.d)continue;
            for(i=h[t.i];i;i=ne[i])if(d[p[i]]>t.d+w[i])
            {
                t1.d=d[p[i]]=t.d+w[i];
                t1.i=p[i];
                H.push(t1);
            }
        }
        printf("%.5lf\n",(double)d[v]);
    }
    return 0;
}