func_code_string: #include <bits/stdc++.h>   using namespace std;   const double fs = 6e-2, Pi = acos(-1.0);   struct point {     double x, y;   } p[4];   double a, b, c, r, S, C, P, C1, A1, B1, R1, Ans;   double s(point a, point b) {     return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));   }   double gcd(double a, double b) {     return (fabs(b) > fs) ? gcd(b, fmod(a, b)) : a;   }   int main() {     for (int i = 1; i <= 3; ++i) scanf( %lf%lf , &p[i].x, &p[i].y);     a = s(p[1], p[2]), b = s(p[2], p[3]), c = s(p[1], p[3]), P = (a + b + c) / 2;     S = sqrt(P * (P - a) * (P - b) * (P - c)), r = a * b * c / (4 * S);     C1 = acos(1 - c * c / (2 * r * r)), A1 = acos(1 - a * a / (2 * r * r)),     B1 = 2 * Pi - A1 - C1;     R1 = gcd(A1, gcd(B1, C1));     return printf( %.6lf , (Pi * r * r * sin(R1)) / R1), 0;   }   