// Construct a circular arc from (2, 1) to (1, 2)
// with center point at (1, 1) and orientation counterclockwise.
// Use a builderEx convenience method or use a builderEx constructor.
MapPoint toPt = MapPointBuilderEx.CreateMapPoint(1, 2);
MapPoint fromPt = MapPointBuilderEx.CreateMapPoint(2, 1);
Coordinate2D centerPtCoord = new Coordinate2D(1, 1);
// BuilderEx convenience methods don't need to run on the MCT.
EllipticArcSegment circularArc = EllipticArcBuilderEx.CreateCircularArc(fromPt, toPt, centerPtCoord, ArcOrientation.ArcCounterClockwise);
// BuilderEx constructors need to run on the MCT.
EllipticArcBuilderEx cab = new EllipticArcBuilderEx(fromPt, toPt, centerPtCoord, ArcOrientation.ArcCounterClockwise);
EllipticArcSegment otherCircularArc = cab.ToSegment();