#include <bits/stdc++.h>
#define FOR(i, l, r) for(int i = (l); i <= (r); i++)
#define ROF(i, r, l) for(int i = (r); i >= (l); i--)
#define ll long long
#define vi vector <int>
#define sz(a) ((int) (a).size())
#define fi first
#define se second
#define ld long double
using namespace std;
const int N = 1e5 + 10;
const ld phi = (1 + sqrtl(5.L)) / 2;
int n;
int x[N], y[N];
ld ydel[N];
ll sqx[N];
ld A, B, ans;
ld X;
ld calc2(ld a, ld b) {
    B = b;
    ld mx = -1. / 0., mn = 1. / 0.;
    FOR(i, 1, n) {
        ld v = ydel[i] - b * x[i];
        mx = max(mx, v), mn = min(mn, v);
    }
    ans = min(ans, (mx - mn));
    return (mx - mn);
}
ld calc1(ld a) {
    FOR(i, 1, n) ydel[i] = y[i] - a * sqx[i];
    A = a;
    ld l = -1e13, r = 1e13;
    ld m1 = (l * phi + r) / (phi + 1), m2 = (l + r * phi) / (phi + 1);
    ld v1 = calc2(a, m1), v2 = calc2(a, m2);
    FOR(i, 1, 120) {
        if(v1 < v2) {
            r = m2;
            m2 = m1, v2 = v1;
            m1 = (l * phi + r) / (phi + 1), v1 = calc2(a, m1);
        } else {
            l = m1;
            m1 = m2, v1 = v2;
            m2 = (l + r * phi) / (phi + 1), v2 = calc2(a, m2);
        }
    }
    return calc2(a, l);
}
ld calc() {
    ld l = -1e7 / X, r = 1e7 / X;
    ld m1 = (l * phi + r) / (phi + 1), m2 = (l + r * phi) / (phi + 1);
    ld v1 = calc1(m1), v2 = calc1(m2);
    FOR(i, 1, 90) {
        if(v1 < v2) {
            r = m2;
            m2 = m1, v2 = v1;
            m1 = (l * phi + r) / (phi + 1), v1 = calc1(m1);
        } else {
            l = m1;
            m1 = m2, v1 = v2;
            m2 = (l + r * phi) / (phi + 1), v2 = calc1(m2);
        }
    }
    return calc1(l);
}
int CT = 0;
void rmain() {
    ans = 1. / 0.;
    cin >> n;
    int mx = 2e6, my = 2e6;
    FOR(i, 1, n) cin >> x[i] >> y[i], mx = min(mx, x[i]), my = min(my, y[i]);
    X = 1;
    FOR(i, 1, n) x[i] -= mx, y[i] -= my, X = max(X, (ld)x[i]), sqx[i] = (ll)x[i] * x[i];
    calc();
    // cerr << fixed << setprecision(20) << A <<" " << B << endl;
    cout << fixed << setprecision(20) << ans * ans / 4 << "\n";
}
int main() {
    ios :: sync_with_stdio(0), cin.tie(0);
    int T;
    for(cin >> T; T--; ) rmain();
}