#include <cmath>
#include <cstdio>
#include <iomanip>
#include <iostream>
#include <map>
#include <vector>
using namespace std;

typedef pair<double,double> PDD;
typedef vector<PDD> VPDD;

PDD operator + (PDD a, PDD b) {
    return PDD(a.first + b.first, a.second + b.second);
}

PDD operator - (PDD a, PDD b) {
    return PDD(a.first - b.first, a.second - b.second);
}

PDD operator * (PDD a, double b) {
    return PDD(a.first * b, a.second * b);
}

double dot(PDD a, PDD b) {
    return a.first * b.first + a.second * b.second;
}

double xpr(PDD a, PDD b) {
    return a.second * b.first - a.first * b.second;
}

PDD norm(PDD x) {
    return PDD(x.second, -x.first);
}

ostream &operator << (ostream &out, const PDD &x) {
    return out << '('
	       << setprecision(2) << x.first
	       << ','
	       << setprecision(2) << x.second
	       << ')';
}

#define EPS 1e-6

int main(void) {
    int cases; cin >> cases;
    for (int casei = 1; casei <= cases; ++casei) {
	int n; cin >> n;
	
	VPDD pts;
	for (int i = 0; i < n; ++i) {
	    double x, y; cin >> x >> y;
	    pts.push_back(PDD(x, y));
	}
	
	// trick to make wrap-around work without needing mod
	pts.push_back(pts[0]);

	double area = 0.0;
	for (int i = 0; i < n; ++i) {
	    PDD a = pts[i], b = pts[i+1];

	    // range of line which is included in final shape
	    double lo = -1e9;
	    double hi = +1e9;

	    for (int j = 0; j < n; ++j) {
		if (i == j) continue;

		PDD c = pts[j], d = pts[j+1];

		// direction of crossing
		double dir = dot(norm(b-a), d-c);

		// s at point of intersection (or NaN if parallel)
		double s = xpr(d-c, a-c) / xpr(b-a, d-c);
		
		if (abs(dir) < EPS) {
		    // parallel lines
		    double pdir = dot(b-a, d-c); // +ve if same direction
		    double side = dot(norm(b-a), d-a); // +ve if right
		    
		    // excluded by same dir to the right or opposite
		    // dir to the left.
		    if (pdir * side > EPS) lo = 1e9;
		}
		else if (dir > 0) {
		    // crossing from left to right
		    hi = min(hi, s);
		}
		else {
		    // crossing from right to left
		    lo = max(lo, s);
		}
	    }
	    
	    if (lo < hi) {
		// if there is some line left, add it to the area
		area += xpr(a + (b-a) * lo, a + (b-a) * hi) * 0.5;
	    }
	}

	// print the final area
	printf("%0.2lf\n", area);
    }
    return 0;
}