#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;
double x1,y11,k,b,a;
// 积分
double f(double x)    // 不定积分值
{
    return a*(x-x1)*(x-x1)*(x-x1)/3.0 - k/2*x*x+(y11-b)*x;
}


int main() {
    double x2,y2,x3,y3;
    int t;
    cin>>t;
    while(t--)
    {
        cin>>x1>>y11>>x2>>y2>>x3>>y3;
        a=(y3-y11)/((x3-x1)*(x3-x1));
        k=(y3-y2)/(x3-x2);
        b=y3-k*x3;
        printf("%.2f\n",f(x3)-f(x2));  // 定积分代入上下限
    }

    return 0;
}