#include <cmath>
#include <cstdio>

const double PI=acos(0)*2;

int main()
{
	freopen("hungry.in","r",stdin);
	freopen("hungry.out","w",stdout);
	int T;
	scanf("%d",&T);
	while(T--)
	{
		int L,D,S;
		scanf("%d%d%d",&L,&D,&S);
		double rp=S-sqrt(D*D+L*L/4.0);
		if (rp<=0)
		{
			if (S<=D)
				printf("%.2lf\n",PI*S*S);
			else
			{
				double alpha=acos(D/double(S));
				printf("%.2lf\n",PI*S*S*(PI-alpha)/PI+L*D/2.0);
			}
			continue;
		}
		double alpha=atan2(L/2.0,D);
		double re=PI*S*S*(PI-alpha)/PI+D*L/2.0;
		double p=rp*rp-L*L/4.0;
		if (p<0)
		{
			re+=PI*rp*rp*(PI/2+alpha)/PI;
			printf("%.2lf\n",re);
			continue;
		}
		else p=sqrt(p);
		re+=p*L/2.0;
		double beta=atan2(p,L/2.0);
		re+=PI*rp*rp*(PI/2+alpha-beta)/PI;
		printf("%.2lf\n",re);
	}
	return 0;
}