float RadExcircle(float A, float B, float C)
{
    // Circumradius formula: R = abc / (4*K)
    // where K is the area (using Heron's formula)
    float s = (A + B + C) / 2.0;
    float K = sqrt(s * (s - A) * (s - B) * (s - C));
    return (A * B * C) / (4.0 * K);
}