#include <bits/stdc++.h>
#define int long long
#define double long double
#define endl '\n'

using namespace std;

const int INF = 0x3f3f3f3f3f3f3f3f;
const double eps = 1e-6;

typedef pair<int, int> PII;

struct Node
{
    double degree;
    int count;
};

void init()
{
    // 可用于初始化全局变量或执行必要的设置
}

void solve()
{
    int n, k;
    cin >> n >> k;

    vector<array<int, 2>> points(n + 1);
    vector<double> degrees(n + 1);
    vector<Node> aa;

    for (int i = 1; i <= n; i++)
    {
        cin >> points[i][0] >> points[i][1];
        degrees[i] = atan2(points[i][1], points[i][0]);
        if (degrees[i] < 0)
        {
            degrees[i] += 2.0 * atan2(0, -1);
        }
    }

    sort(degrees.begin() + 1, degrees.end());

    for (int i = 1; i <= n; i++)
    {
        if (!aa.empty() && degrees[i] == aa.back().degree)
        {
            aa.back().count++;
        }
        else
        {
            aa.push_back({degrees[i], 1});
        }
    }

    int m = aa.size();
    vector<int> sum_cnt(2 * m);
    for (int i = 0; i < m; i++)
    {
        aa.push_back({aa[i].degree + 2.0 * atan2(0, -1), aa[i].count});
    }

    sum_cnt[0] = aa[0].count;
    for (int i = 1; i < 2 * m; i++)
    {
        sum_cnt[i] = sum_cnt[i - 1] + aa[i].count;
    }

    double ans = 0;
    auto calc = [&](int i, int j)
    {
        if (i == 0)
        {
            return sum_cnt[j] - max(aa[i].count, aa[j].count);
        }
        else
        {
            return sum_cnt[j] - sum_cnt[i - 1] - max(aa[i].count, aa[j].count);
        }
    };
    for (int i = 0, j = 0; i < m; i++)
    {
        j = max(i, j);
        while (j + 1 <= i + m && (calc(i, j)) < k)
        {
            j++;
        }
        // cerr << i << " " << j << endl;

        ans = max(ans, aa[j].degree - aa[i].degree);
    }

    cout << ans << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cout << fixed << setprecision(10);

    int t;
    cin >> t;
    init();

    while (t--)
    {
        solve();
    }

    return 0;
}