#include<random>
#include<iostream>
#include<complex>
#include<cmath>
#include<cstdio>
using std::cin;
using std::cout;
using db = double;
using cp = std::complex<db>;
const int N = 699;
std::pair<cp, cp> get() {
	int x1, y1;
	int x2, y2;
	cin >> x1 >> y1;
	cin >> x2 >> y2;
	return {cp(x1, y1), cp(x2, y2)};
}


cp A, B, C;
db a, a4, a2;
db sqa;
db cbrta;

db eval(db t) {
	cp X = A * t + C;
	db b = B.real() * X.real() + B.imag() * X.imag();
	db c = std::norm(X);
	db s = a + b + c;
	db val1 = std::sqrt(std::max(s, 0.));
	db val0 = std::sqrt(c);
	db ans = b / a4 * (val1 - val0);
	ans += val1 / 2;

	db xx = (a4 * c - b * b) / cbrta;
	if(xx > 1e-9)  {
		db w = std::fabs((a2 + b + sqa * val1) / (b + sqa * val0));
		if(w > 1e-9)
			ans += xx * log(w); 
	}
	return ans;
}
int main() {
	std::ios::sync_with_stdio(false), cin.tie(0);
	int T;
	cin >> T;
	for(int i = 0;i < T;++i) {
		auto [a0, b0] = get();
		auto [a1, b1] = get();
		if(std::abs(a0 - b0) > std::abs(a1 - b1)) {
			std::swap(a0, a1);
			std::swap(b0, b1);
		}
		A = (b0 - a0);
		B = -(b1 - a1);
		C = a0 - a1;
		a = std::norm(B);
		a4 = a * 4;
		a2 = a * 2;
		sqa = std::sqrt(std::norm(B)) * 2;
		B *= 2;
		cbrta = std::sqrt(a * a * a) * 8;

		int cnt = 0;
		db sum = (eval(0) + eval(1)) * 17
			+ 59 * (eval(1. / N) + eval(1 - 1. / N))
			+ 43 * (eval(2. / N) + eval(1 - 2. / N))
			+ 49 * (eval(3. / N) + eval(1 - 3. / N));
		cnt += (17 + 59 + 43 + 49) * 2;
		cnt += (N - 7) * 48;
		for(int i = 4;i <= N - 4;++i) {
			sum += eval((db)i / N) * 48;
		}
		sum /= cnt;
		printf("%.11lf\n", sum);
	}
}