#include <bits/stdc++.h>
#define inf 1000000007
#define mod 1000000007
// #define int long long
// #pragma GCC optimize("Ofast","inline","-ffast-math")
// #pragma GCC target("avx,sse2,sse3,sse4,mmx")
using namespace std;
template <typename T> void read(T &x){
	x=0;char ch=getchar();int fh=1;
	while (ch<'0'||ch>'9'){if (ch=='-')fh=-1;ch=getchar();}
	while (ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
	x*=fh;
}
template <typename T> void write(T x) {
	if (x<0) x=-x,putchar('-');
	if (x>9) write(x/10);
	putchar(x%10+'0');
}
template <typename T> void writeln(T x) {
	write(x);
	puts("");
}
const double eps=1e-8;
double solve(double x,double y,double xx,double yy)
{
	return fabs(x-xx)+fabs(y-yy);
}
signed main()
{
	// freopen(".in","r",stdin);
	// freopen(".out","w",stdout);
	int tc;read(tc);
	while(tc--)
	{
		int x11,y11,x12,y12;
		int x21,y21,x22,y22;
		read(x11);read(y11);read(x12);read(y12);
		read(x21);read(y21);read(x22);read(y22);
		double xc=(x21+x22)/2.0,yc=(y21+y22)/2.0;
		double r=sqrtl((x21-x22)*(x21-x22)+(y21-y22)*(y21-y22))/2.0;
		double ans=min({
			solve(xc+r*sqrt(2)/2,yc+r*sqrt(2)/2,(x11+x12)/2.0,(y11+y12)/2.0),
			solve(xc-r*sqrt(2)/2,yc+r*sqrt(2)/2,(x11+x12)/2.0,(y11+y12)/2.0),
			solve(xc+r*sqrt(2)/2,yc-r*sqrt(2)/2,(x11+x12)/2.0,(y11+y12)/2.0),
			solve(xc-r*sqrt(2)/2,yc-r*sqrt(2)/2,(x11+x12)/2.0,(y11+y12)/2.0)
		});
		printf("%.10lf\n",ans);
	}
	return 0;
}