\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 r81821 = a;
double r81822 = b;
double r81823 = r81821 + r81822;
double r81824 = c;
double r81825 = r81823 + r81824;
double r81826 = 2.0;
double r81827 = r81825 / r81826;
double r81828 = r81827 - r81821;
double r81829 = r81827 * r81828;
double r81830 = r81827 - r81822;
double r81831 = r81829 * r81830;
double r81832 = r81827 - r81824;
double r81833 = r81831 * r81832;
double r81834 = sqrt(r81833);
return r81834;
}