#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rep1(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < (t); ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define em emplace
#define pob pop_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define newline puts("")
#define vc vector
using namespace std;
template<class T> using vv = vc<vc<T>>;
template<class T> using PQ = priority_queue<T,vc<T>,greater<T>>;
using uint = unsigned; using ull = unsigned long long;
using vi = vc<int>; using vvi = vv<int>; using vvvi = vv<vi>;
using ll = long long; using vl = vc<ll>; using vvl = vv<ll>; using vvvl = vv<vl>;
using P = pair<int,int>; using vp = vc<P>; using vvp = vv<P>; using LP = pair<ll,ll>;
int geti(){int x;scanf("%d",&x);return x;}
vi pm(int n, int s=0) { vi a(n); iota(rng(a),s); return a;}
template<class T1,class T2>istream& operator>>(istream&i,pair<T1,T2>&v){return i>>v.fi>>v.se;}
template<class T1,class T2>ostream& operator<<(ostream&o,const pair<T1,T2>&v){return o<<v.fi<<","<<v.se;}
template<class T>istream& operator>>(istream&i,vc<T>&v){rep(j,sz(v))i>>v[j];return i;}
template<class T>string join(const T&v,const string&d=""){stringstream s;rep(i,sz(v))(i?s<<d:s)<<v[i];return s.str();}
template<class T>ostream& operator<<(ostream&o,const vc<T>&v){if(sz(v))o<<join(v," ");return o;}
template<class T>void vin(vc<T>&a){int n;cin>>n;a=vc<T>(n);cin>>a;}
template<class T>void vin(vv<T>&a){int n,m;cin>>n>>m;a=vv<T>(n,vc<T>(m));cin>>a;}
template<class T1,class T2>void operator--(pair<T1,T2>&a,int){a.fi--;a.se--;}
template<class T1,class T2>void operator++(pair<T1,T2>&a,int){a.fi++;a.se++;}
template<class T>void operator--(vc<T>&a,int){for(T&x:a)x--;}
template<class T>void operator++(vc<T>&a,int){for(T&x:a)x++;}
template<class T1,class T2>void operator+=(vc<T1>&a,T2 b){for(T1&x:a)x+=b;}
template<class T1,class T2>void operator-=(vc<T1>&a,T2 b){for(T1&x:a)x-=b;}
template<class T1,class T2>void operator*=(vc<T1>&a,T2 b){for(T1&x:a)x*=b;}
template<class T1,class T2>void operator/=(vc<T1>&a,T2 b){for(T1&x:a)x/=b;}
template<class T>void operator+=(vc<T>&a,const vc<T>&b){a.insert(a.end(),rng(b));}
template<class T1,class T2>pair<T1,T2>operator+(const pair<T1,T2>&a,const pair<T1,T2>&b){return {a.fi+b.fi,a.se+b.se};}
template<class T1,class T2>pair<T1,T2>operator-(const pair<T1,T2>&a,const pair<T1,T2>&b){return {a.fi-b.fi,a.se-b.se};}
template<class T>pair<T,T>operator*(const pair<T,T>&a,T b){return {a.fi*b,a.se*b};}
template<class T1,class T2>bool mins(T1& x,const T2&y){if(y<x){x=y;return true;}else return false;}
template<class T1,class T2>bool maxs(T1& x,const T2&y){if(x<y){x=y;return true;}else return false;}
template<class T>T min(const vc<T>&a){return *min_element(rng(a));}
template<class T>T max(const vc<T>&a){return *max_element(rng(a));}
template<class Tx,class Ty>Tx dup(Tx x, Ty y){return (x+y-1)/y;}
template<class T>ll suma(const vc<T>&a){ll s=0;for(auto&&x:a)s+=x;return s;}
template<class T>ll suma(const vv<T>&a){ll s=0;for(auto&&x:a)s+=suma(x);return s;}
template<class T>void uni(T&a){sort(rng(a));a.erase(unique(rng(a)),a.end());}
template<class T>void prepend(vc<T>&a,const T&x){a.insert(a.begin(),x);}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return;}
#define yes { puts("Yes"); return;}
#define no { puts("No"); return;}
#define rtn(x) { cout<<(x)<<'\n'; return;} // flush!
#define yn {puts("Yes");}else{puts("No");}
using vd = vc<double>;

// geom
const double inf = 1e6;
const double PI = acos(-1.0);
inline double toRad(double deg){ return deg * PI / 180.0;}

struct V {
  double x, y;
  V(double x=0, double y=0):x(x),y(y){}
  V operator+(const V& t) const { return V(x+t.x,y+t.y);}
  V operator-(const V& t) const { return V(x-t.x,y-t.y);}
  V operator*(double t) const { return V(x*t,y*t);}
  V operator/(double t) const { return V(x/t,y/t);}
  V operator*(const V& t) const { return V(x*t.x-y*t.y,x*t.y+y*t.x);}
  V operator/(const V& t) const { return *this*V(t.x,-t.y)/t.norm2();}
  V& operator+=(const V& t) { x += t.x; y += t.y; return *this;}
  V& operator-=(const V& t) { x -= t.x; y -= t.y; return *this;}
  V& operator*=(double t) { x *= t; y *= t; return *this;}
  V& operator/=(double t) { x /= t; y /= t; return *this;}
  V& operator*=(const V& t) { return *this = *this*t;}
  V& operator/=(const V& t) { return *this = *this/t;}
  double dot(const V& t) const { return x*t.x + y*t.y;}
  double cross(const V& t) const { return x*t.y - y*t.x;}
  double norm2() const { return x*x + y*y;}
  double norm() const { return sqrt(x*x + y*y);}
  V rev() const { return V(-x,-y);}
  V normalize() const { return V(x/norm(), y/norm());}
  V rotate90() const { return V(-y,x);}
  V rotate(const V& a, double rad) const {
    return V(a.x + cos(rad)*(x-a.x) - sin(rad)*(y-a.y),
             a.y + sin(rad)*(x-a.x) + cos(rad)*(y-a.y));
  }
  bool operator<(const V& a) const { return abs(x - a.x) > eps ? x < a.x : y < a.y;}
  bool operator==(const V& a) const { return abs(x - a.x) < eps && abs(y - a.y) < eps;}
  // inline int side() const {
  //   if (abs(y) < eps) {
  //     if (abs(x) < eps) return 0;
  //     return x > 0 ? 1 : 3;
  //   }
  //   return y > 0 ? 2 : 4;
  // }
  // bool operator<(const V& a) const {
  //   int s = side(), sa = a.side();
  //   if (s != sa) return s < sa;
  //   return cross(a) > 0;
  // }
};
istream& operator>>(istream&i,V&a){i>>a.x>>a.y;return i;}
ostream& operator<<(ostream&o,const V&a){o<<a.x<<','<<a.y;return o;}

struct Line {
  V s, t;
  Line(V s=V(0,0), V t=V(0,0)):s(s),t(t){}
  V dir() const { return t-s;}
  V normalize() const { return dir().normalize();}
  double norm() const { return dir().norm();}
  /* +1: s-t,s-p : ccw
   * -1: s-t,s-p : cw
   * +2: t-s-p
   * -2: s-t-p
   *  0: s-p-t */
  int ccw(const V& p) const {
    if (dir().cross(p-s) > eps) return +1;
    if (dir().cross(p-s) < -eps) return -1;
    if (dir().dot(p-s) < -eps) return +2;
    if (dir().dot(t-p) < -eps) return -2;
    return 0;
  }
  bool touch(const Line& l) const {
    int a = ccw(l.s)*ccw(l.t), b = l.ccw(s)*l.ccw(t);
    return !a || !b || (a == -1 && b == -1);
  }
  double distLP(const V& p) const { return abs(dir().cross(p-s)/norm());}
  double distSP(const V& p) const {
    if (dir().dot(p-s) < eps) return (p-s).norm();
    if (dir().rev().dot(p-t) < eps) return (p-t).norm();
    return distLP(p);
  }
  double distSS(const Line& l) const {
    if(touch(l)) return 0;
    return min(min(distSP(l.s),distSP(l.t)),min(l.distSP(s),l.distSP(t)));
  }
  V proj(const V& p) const {
    double a = (p-s).dot(dir())/dir().norm2();
    return s + dir()*a;
  }
  Line mid() const {
    V p = (s+t)/2, q = dir();
    return Line(p, p+V(q.y,-q.x));
  }
  V xp(const Line& l) const {
    V a = dir(), b = l.dir();
    if (abs(b.cross(a)) < eps) return V(inf,inf);
    return s + a*(b.cross(l.s-s)/b.cross(a));
  }
};

using Poly = vector<V>;
inline V pnxt(Poly& p, int i) { return p[(i+1)%sz(p)];}
inline V ppre(Poly& p, int i) { return p[(i-1+sz(p))%sz(p)];}
inline Line pline(Poly& p, int i) { return Line(p[i],pnxt(p,i));}
Poly conv(Poly a) {
  int n = sz(a);
  sort(rng(a));
  if (n <= 2) return a;
  Poly res(n*2);
  int k = 0;
  for (int i = 0; i < n; ++i){
    while (k > 1 && Line(res[k-1],res[k-2]).ccw(a[i]) != 1) --k; // <= -1 ok line
    res[k++] = a[i];
  }
  int pre = k;
  for (int i = n - 2; 0 <= i; --i){
    while (k > pre && Line(res[k-1],res[k-2]).ccw(a[i]) != 1) --k; // <= -1 ok line
    res[k++] = a[i];
  }
  res.resize(k-1);
  return res;
}
double area(Poly& a) {
  double res = 0;
  rep(i,sz(a)-2){
    res += abs(V(a[i+1]-a[0]).cross(V(a[i+2]-a[0])));
  }
  return res/2;
}
Poly convCut(Poly& a, Line b) {
  Poly g;
  rep(i,sz(a)){
    if (b.ccw(a[i]) == 1) g.pb(a[i]);
    Line l(a[i],pnxt(a,i));
    V x = b.xp(l);
    if (l.ccw(x) == 0 && !(a[i] == x)) g.pb(x);
  }
  return g;
}
vector<Poly> voronoi(Poly& p, Poly& c) {
  vector<Poly> g;
  rep(i,sz(p)) g.pb(c);
  rep(i,sz(p))rep(j,sz(p)) {
    if (i == j) continue;
    Line l = Line(p[i],p[j]).mid();
    if (l.ccw(p[i]) != 1) swap(l.s,l.t);
    g[i] = convCut(g[i],l);
  }
  return g;
}

struct Circle {
  V o; double r;
  Circle(V o=V(0,0), double r=0):o(o),r(r){}
  Poly xp(Circle c) {
    Poly res;
    double d = (o-c.o).norm();
    if (d > r+c.r) return res;
    if (d+min(r, c.r) < max(r, c.r)+eps) return Poly();
    double rcos = (d*d + r*r - c.r*c.r) / (2.0*d);
    double rsin = sqrt(r*r - rcos*rcos);
    V a = (c.o-o).normalize();
    res.pb(o + V(a.x*rcos - a.y*rsin, a.x*rsin + a.y*rcos));
    res.pb(o + V(a.x*rcos + a.y*rsin, -a.x*rsin + a.y*rcos));
    return res;
  }
  Poly xp(Line l) {
    Poly res;
    double h = l.distLP(o);
    if (h > r+eps) return res;
    V p = l.proj(o);
    double d = sqrt(max(0.0, r*r-h*h));
    V q = l.normalize();
    res.pb(p + q*d);
    res.pb(p - q*d);
    return res;
  }
  bool in(V p) { return (p-o).norm() < r+eps;}
  bool touch(Circle c) { return (c.o-o).norm() < c.r+r+eps;}
  double distCC(Circle c) { return max((c.o-o).norm()-c.r-r, 0.0);}
  Poly tang(V p) {
    Poly res;
    double a = (p-o).norm2(), b = a-r*r;
    if (b < -eps) return res;
    b = max(b,0.0);
    V h = o + (p-o)*(r*r/a);
    V v = (p-o).rotate90()*(r*sqrt(b)/a);
    res.pb(h+v);
    res.pb(h-v);
    return res;
  }
  vector<Line> tangC(Circle c) {
    vector<Line> res;
    if (abs(r-c.r) < eps) {
      V v = (c.o-o).rotate90().normalize()*r;
      res.pb(Line(o+v,c.o+v));
      res.pb(Line(o-v,c.o-v));
    } else {
      V p = (o*-c.r + c.o*r) / (r-c.r);
      Poly a = tang(p), b = c.tang(p);
      rep(i,sz(a))rep(j,sz(b)) {
        if (abs(Line(a[i],b[j]).ccw(p)) == 2) res.pb(Line(a[i],b[j]));
      }
    }
    V p = (o*c.r + c.o*r)/(r+c.r);
    Poly a = tang(p), b = c.tang(p);
    rep(i,sz(a))rep(j,sz(b)) {
      if (Line(a[i],b[j]).ccw(p) == 0) res.pb(Line(a[i],b[j]));
    }
    return res;
  }
  double TriArea(V a, V b) {
    if (a == o || b == o) return 0;
    a = a-o; b = b-o;
    double d = a.cross(b)/2;
    if (a.norm() > r+eps || b.norm() > r+eps){
      double e = (atan2(a.y,a.x)-atan2(b.y,b.x))/(PI*2);
      while (e < 0) e += 1;
      while (e > 1) e -= 1;
      return r*r*PI * min(e,1-e) * (d<0?-1:1);
    }
    return d;
  }
  double PolyArea(Poly p) {
    double res = 0;
    rep(i,sz(p)){
      V a = p[i], b = p[(i+1)%sz(p)];
      Poly x = xp(Line(a,b));
      if (sz(x) == 2 && (x[0]-a).norm() > (x[1]-a).norm()) swap(x[0],x[1]);
      Poly ps;
      ps.pb(a);
      rep(j,sz(x)) if (Line(a,b).ccw(x[j]) == 0) ps.pb(x[j]);
      ps.pb(b);
      rep(i,sz(ps)-1) res += TriArea(ps[i],ps[i+1]);
    }
    return abs(res);
  }
};
// geom

struct Solver {
  void solve() {
    int n, k;
    cin>>n>>k;
    Poly ps(n);
    cin>>ps;

    vd a;
    rep(i,n) a.pb(atan2(ps[i].y,ps[i].x));
    sort(rng(a));
    rep(i,n) a.pb(a[i]+PI*2);
    double ans = 0;
    rep(i,n) {
      maxs(ans, a[i+k]-a[i]);
    }
    printf("%.10f\n",ans);
  }
};

int main() {
  // cin.tie(nullptr); ios::sync_with_stdio(false);
  int ts = 1;
  scanf("%d",&ts);
  rep1(ti,ts) {
    Solver solver;
    solver.solve();
  }
  return 0;
}