/// <summary>
/// Radian angle from a centre to another point
/// </summary>
/// <param name="centre"></param>
/// <param name="point"></param>
/// <returns name="rad">Radians</returns>
internal static double RadAngle(DSPoint centre, DSPoint point)
{
Vertex v1 = Vertex.ByCoordinates(centre.X, centre.Y, centre.Z);
Vertex v2 = Vertex.ByCoordinates(point.X, point.Y, point.Z);
return(Vertex.RadAngle(v1, v2));
}