\sqrt{\left(\left(\frac{\left(a + b\right) + c}{2} \cdot \left(\frac{\left(a + b\right) + c}{2} - a\right)\right) \cdot \left(\frac{\left(a + b\right) + c}{2} - b\right)\right) \cdot \left(\frac{\left(a + b\right) + c}{2} - c\right)}double f(double a, double b, double c) {
double r100867 = a;
double r100868 = b;
double r100869 = r100867 + r100868;
double r100870 = c;
double r100871 = r100869 + r100870;
double r100872 = 2.0;
double r100873 = r100871 / r100872;
double r100874 = r100873 - r100867;
double r100875 = r100873 * r100874;
double r100876 = r100873 - r100868;
double r100877 = r100875 * r100876;
double r100878 = r100873 - r100870;
double r100879 = r100877 * r100878;
double r100880 = sqrt(r100879);
return r100880;
}