/// <summary>
/// Initializes triangle object using three points.
/// </summary>
public Triangle(Point3d A, Point3d B, Point3d C)
{
if (Point3d.CollinearPoints(A, B, C))
{
throw new Exception("Collinear points");
}
_a = A.Copy();
_b = B.Copy();
_c = C.Copy();
}
