// Arc
public Arc ArcToSpeckle(CircularArc3d arc)
{
var _arc = new Arc(PlaneToSpeckle(arc.GetPlane()), arc.Radius, arc.StartAngle, arc.EndAngle, Math.Abs(arc.EndAngle - arc.StartAngle), ModelUnits);
_arc.startPoint = PointToSpeckle(arc.StartPoint);
_arc.endPoint = PointToSpeckle(arc.EndPoint);
_arc.domain = IntervalToSpeckle(arc.GetInterval());
_arc.length = arc.GetLength(arc.GetParameterOf(arc.StartPoint), arc.GetParameterOf(arc.EndPoint), tolerance);
_arc.bbox = BoxToSpeckle(arc.OrthoBoundBlock);
return(_arc);
}