#if __INCLUDE_LEVEL__ == 0

#include __BASE_FILE__

void Solve() {
  int n, k;
  IN(n, k);
  vector<int> x(n), y(n);
  vector<double> a(n + n);
  for (int i : Rep(0, n)) {
    IN(x[i], y[i]);
    a[i] = atan2(y[i], x[i]);
    a[i + n] = a[i] + 2 * M_PI;
  }
  ranges::sort(a);
  double ans = 0;
  for (int i = 0; i + k < Sz(a); ++i) {
    SetMax(ans, a[i + k] - a[i]);
  }
  OUT(ans);
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout << setprecision(DBL_DECIMAL_DIG);

  int t;
  IN(t);
  while (t--) {
    Solve();
  }
}

#elif __INCLUDE_LEVEL__ == 1

#include <bits/stdc++.h>

template <class T> concept Range = std::ranges::range<T> && !std::convertible_to<T, std::string_view>;
template <class T> concept Tuple = std::__is_tuple_like<T>::value && !Range<T>;

namespace std {

istream& operator>>(istream& is, Range auto&& r) {
  for (auto&& e : r) is >> e;
  return is;
}
istream& operator>>(istream& is, Tuple auto&& t) {
  apply([&](auto&... xs) { (is >> ... >> xs); }, t);
  return is;
}

ostream& operator<<(ostream& os, Range auto&& r) {
  auto sep = "";
  for (auto&& e : r) os << exchange(sep, " ") << e;
  return os;
}
ostream& operator<<(ostream& os, Tuple auto&& t) {
  auto sep = "";
  apply([&](auto&... xs) { ((os << exchange(sep, " ") << xs), ...); }, t);
  return os;
}

}  // namespace std

using namespace std;

#define LAMBDA2(x, y, ...) ([&](auto&& x, auto&& y) -> decltype(auto) { return __VA_ARGS__; })
#define Rep(...) [](int l, int r) { return views::iota(min(l, r), r); }(__VA_ARGS__)
#define Sz(r) int(size(r))
#define SetMax(...) LAMBDA2(x, y, x < y && (x = y, 1))(__VA_ARGS__)
#define IN(...) (cin >> forward_as_tuple(__VA_ARGS__))
#define OUT(...) (cout << forward_as_tuple(__VA_ARGS__) << '\n')

#endif  // __INCLUDE_LEVEL__ == 1