#include <fstream>
#include <cmath>
#include <iomanip>

#define I_F "hungry.in"
#define O_F "hungry.out"
#define MAXn 100

using namespace std;

double l[MAXn], d[MAXn], s[MAXn];
int n;
double ans[MAXn];
const double pi=3.14159265358979323946264338325027988;

void Input();
inline double Sqr(double);
inline double S1(double,double);
inline double S2(double,double);
void Sum();
void Output();

int main()
{
	Input();
	Sum();
	Output();
	return 0;
}

void Input()
{
	ifstream fin(I_F);
	fin>>n;
	for (int i=0; i<n; i++)
		fin>>l[i]>>d[i]>>s[i];
	fin.close();
}

inline double Sqr(double x)
{
	return (x*x);
}

inline double S1(double x, double r)
{
	return (x/(pi*2)*Sqr(r));
}

inline double S2(double a, double h)
{
	return (a*h/2);
}

void Sum()
{
	for (int i=0; i<n; i++)
		if (s[i]<=d[i])
			ans[i]=S1(2*pi,s[i]);
		else if (s[i]<=sqrt(Sqr(d[i])+Sqr(l[i]/2)))
			ans[i]=(S1(pi-atan(l[i]/2/d[i]),s[i])+S2(l[i]/2,d[i]))*2;
		else if ((s[i]-sqrt(Sqr(d[i])+Sqr(l[i]/2)))<=(l[i]/2))
			ans[i]=(S1(pi-atan(l[i]/2/d[i]),s[i])+S1(pi-atan(d[i]*2/l[i]),s[i]-sqrt(Sqr(d[i])+Sqr(l[i]/2)))+S2(l[i]/2,d[i]))*2;
		else
			ans[i]=(S1(pi-atan(l[i]/2/d[i]),s[i])+S1(pi-atan(d[i]*2/l[i])-acos(l[i]/2/sqrt(Sqr(d[i])+Sqr(l[i]/2))),s[i])+S2(l[i]/2,d[i]+sqrt(Sqr(s[i]-sqrt(Sqr(d[i])+Sqr(l[i]/2)))-Sqr(l[i]/2))))*2;
}

void Output()
{
	ofstream fout(O_F);
	for (int i=0; i<n; i++)
		fout<<setiosflags(ios::fixed)<<setprecision(2)<<ans[i]<<'\n';
	fout.close();
}