#include<algorithm>
#include<chrono>
#include<cmath>
#include<cstdio>
#include<random>
namespace IO{
	const int ARR_SIZE=1<<20;
	#define gc() ((IO::si!=IO::ti||(IO::ti=(IO::si=IO::input)+fread(IO::input,1,IO::ARR_SIZE,stdin))),IO::si!=IO::ti?*(IO::si++):EOF)
	char input[ARR_SIZE],*si=input,*ti=input;
	template<typename T>
	void read(T&num){
		bool flag=true;
		int ch=gc();
		num=0;
		while(ch<48||ch>57){
			if(ch=='-')flag=false;
			ch=gc();
		}
		while(ch>=48&&ch<=57)num=(num<<3)+(num<<1)+(ch^48),ch=gc();
		flag||(num=-num);
	}
}
using IO::read;
typedef long long ll;
typedef double real;
const int maxn=300,maxm=maxn*maxn*2;
const real eps=1e-8,inf=1e18;
std::mt19937 mt(std::chrono::steady_clock::now().time_since_epoch().count());
int n,m,cnt,id[maxn+1];
real sum[maxn+1][maxn+1],len[maxn+1][maxn+1],dp[maxn+1];
struct Vector{
	ll x,y;
	Vector(const ll x=0,const ll y=0):x(x),y(y){}
	void input(){
		read(x),read(y);
	}
	friend Vector operator-(const Vector&A,const Vector&B){
		return Vector(A.x-B.x,A.y-B.y);
	}
	friend bool operator<(const Vector&A,const Vector&B){
		return A.y!=B.y?A.y<B.y:A.x<B.x;
	}
	Vector rotate_90()const{
		return Vector(-y,x);
	}
	bool sign()const{
		return y>0||(y==0&&x>0);
	}
	friend ll Cross(const Vector&A,const Vector&B){
		return A.x*B.y-A.y*B.x;
	}
	friend ll Dot(const Vector&A,const Vector&B){
		return A.x*B.x+A.y*B.y;
	}
}a[maxn+1];
struct Line{
	int s,t,type;
	Vector v;
	friend bool operator<(const Line&A,const Line&B){
		const bool sA=A.v.sign(),sB=B.v.sign();
		if(sA!=sB)return sA>sB;
		ll cross=Cross(A.v,B.v);
		if(cross)return cross>0;
		else return A.type<B.type;
	}
}l[maxm+1],upd[maxm+1];
void init(const int p){
	cnt=0;
	static int perm[maxn+1],mn[maxn+1],id[maxn+1];
	for(int i=p;i<=n;i++)perm[i]=i;
	std::sort(perm+p,perm+n+1,[&](const int x,const int y){
		const ll cross=Cross(a[x]-a[p],a[y]-a[p]);
		if(cross)return cross>0;
		else return len[p][x]<len[p][y];
	});
	for(int i=p;i<=n;i++)mn[i]=1000000000;
	for(int i=p;i<=n;i++)id[perm[i]]=i;
	for(int i=m;i>=1;i--)
		if(l[i].s>=p){
			const int s=l[i].s,t=l[i].t;
			if(l[i].type)upd[++cnt]=l[i];
			else if(t>=p){
				if(s==p||t==p)upd[++cnt]=l[i];
				else if(id[s]<id[t]&&id[t]<mn[s]){
					mn[s]=id[t];
					upd[++cnt]=l[i];
				}
			}
		}
	std::reverse(upd+1,upd+cnt+1);
}
bool check(const int p,const real x){
	for(int i=1;i<=n;i++)dp[i]=-inf;
	dp[p]=-eps;
	for(int i=1,s,t,type;i<=cnt;i++){
		s=upd[i].s,t=upd[i].t,type=upd[i].type;
		if(type==1)dp[s]-=x*len[s][t];
		else dp[t]=std::max(dp[t],dp[s]+Cross(a[s]-a[p],a[t]-a[p])*0.5-x*sum[s][t]);
	}
	return dp[p]>eps;
}
void solve(){
	read(n),m=0;
	for(int i=1;i<=n;i++)a[i].input();
	std::sort(a+1,a+n+1);
	for(int i=1;i<=n;i++)id[i]=i;
	std::shuffle(id+1,id+n+1,mt);
	for(int i=1;i<=n;i++)
		for(int j=i;j<=n;j++)
			len[i][j]=len[j][i]=hypot(a[i].x-a[j].x,a[i].y-a[j].y);
	for(int i=1;i<=n;i++)
		for(int j=1;j<=n;j++)
			if(i!=j){
				sum[i][j]=len[i][j];
				for(int k=1;k<=n;k++)
					if(Cross(a[k]-a[i],a[j]-a[i])>0&&Dot(a[j]-a[i],a[k]-a[i])>=0&&Dot(a[i]-a[j],a[k]-a[j])>0)
						sum[i][j]+=std::min(len[i][k],len[j][k]);
				l[++m]=Line{i,j,0,a[j]-a[i]};
				l[++m]=Line{i,j,1,(a[j]-a[i]).rotate_90()};
			}
	std::sort(l+1,l+m+1);
	real ans=0;
	for(int i=1;i<=n;i++){
		const int u=id[i];
		init(u);
		if(check(u,ans)){
			real l=ans,r=1e6;
			while(r-l>eps){
				real mid=(l+r)/2;
				if(check(u,mid))l=mid;
				else r=mid;
			}
			ans=l;
		}
	}
	printf("%.8lf\n",ans);
}
int main(){
	int T;
	read(T);
	while(T>0)T--,solve();
	return 0;
}