// Construct a circular arc from (2, 1) to (1, 2) with interior pt (1 + sqrt(2)/2, 1 + sqrt(2)/2).
// Use a builderEx convenience method or use a builderEx constructor.
MapPoint fromPt = MapPointBuilderEx.CreateMapPoint(2, 1);
MapPoint toPt = MapPointBuilderEx.CreateMapPoint(1, 2);
Coordinate2D interiorPt = new Coordinate2D(1 + Math.Sqrt(2) / 2, 1 + Math.Sqrt(2) / 2);
// BuilderEx convenience methods don't need to run on the MCT.
EllipticArcSegment circularArc = EllipticArcBuilderEx.CreateCircularArc(fromPt, toPt, interiorPt);
// BuilderEx constructors don't need to run on the MCT.
EllipticArcBuilderEx eab = new EllipticArcBuilderEx(fromPt, toPt, interiorPt);
// do something with the builder
EllipticArcSegment anotherCircularArc = eab.ToSegment();