public new EllipticArcSegment ToSegment()

// 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 dont need to run on the MCT.
EllipticArcBuilderEx eab = new EllipticArcBuilderEx(fromPt, toPt, interiorPt);
// do something with the builder

EllipticArcSegment anotherCircularArc = eab.ToSegment();

// Construct a circular arc counterclockwise from (2, 1) to (1, 2) such that the embedded 
// circle has center point at (1, 1) and radius = 1.
// Use a builderEx convenience method or use a builderEx constructor.

MapPoint fromPt = MapPointBuilderEx.CreateMapPoint(2, 1, SpatialReferences.WGS84);
double chordLength = Math.Sqrt(2);
double chordBearing = 3 * Math.PI / 4;
double radius = 1;
ArcOrientation orientation = ArcOrientation.ArcCounterClockwise;
MinorOrMajor minorOrMajor = MinorOrMajor.Minor;

// BuildeExr convenience methods don't need to run on the MCT.
EllipticArcSegment circularArc = EllipticArcBuilderEx.CreateCircularArc(fromPt, chordLength, chordBearing, radius, orientation, minorOrMajor);

// BuilderEx constructors need to run on the MCT.
EllipticArcBuilderEx cab = new EllipticArcBuilderEx(fromPt, chordLength, chordBearing, radius, orientation, minorOrMajor);
// do something with the builder

EllipticArcSegment anotherCircularArc = cab.ToSegment();

// Construct a circular arc with center point at (0, 0), from angle = 0, 
// central angle = pi/2, radius = 1.
// Use a builderEx convenience method or use a builderEx constructor.

SpatialReference sr4326 = SpatialReferences.WGS84;
Coordinate2D centerPt = new Coordinate2D(0, 0);
double fromAngle = 0;
double centralAngle = Math.PI / 2;
double radius = 1;

// BuilderEx convenience methods don't need to run on the MCT.
EllipticArcSegment circularArc = EllipticArcBuilderEx.CreateCircularArc(fromAngle, centralAngle, centerPt, radius, sr4326);

// BuilderEx constructors dont need to run on the MCT.
EllipticArcBuilderEx cab = new EllipticArcBuilderEx(fromAngle, centralAngle, centerPt, radius, sr4326);
EllipticArcSegment otherCircularArc = cab.ToSegment();

//Create a circle graphic element using a simple line and fill styles.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  Coordinate2D center = new Coordinate2D(2, 4);
  //At 2.x - EllipticArcBuilder eabCir = new EllipticArcBuilder(center, 0.5, esriArcOrientation.esriArcClockwise);
  var eabCir = new EllipticArcBuilderEx(center, 0.5, ArcOrientation.ArcClockwise);
  EllipticArcSegment cir = eabCir.ToSegment();

  //Set symbolology, create and add element to layout
  CIMStroke outline = SymbolFactory.Instance.ConstructStroke(ColorFactory.Instance.BlackRGB, 2.0, SimpleLineStyle.Dash);
  CIMPolygonSymbol circleSym = SymbolFactory.Instance.ConstructPolygonSymbol(ColorFactory.Instance.RedRGB, SimpleFillStyle.Solid, outline);
  //At 2.x - GraphicElement cirElm = LayoutElementFactory.Instance.CreateCircleGraphicElement(layout, cir, circleSym);
  //         cirElm.SetName("New Circle");

  var polyLine = PolylineBuilderEx.CreatePolyline(cir);
  GraphicElement cirElm = ElementFactory.Instance.CreateGraphicElement(layout, polyLine, circleSym, "New Circle");
});

//Create an ellipse graphic with simple line and fill styles.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  Coordinate2D center = new Coordinate2D(2, 2.75);
  //At 2.x - EllipticArcBuilder eabElp = new EllipticArcBuilder(center, 0, 1, 0.45, esriArcOrientation.esriArcClockwise);
  var eabElp = new EllipticArcBuilderEx(center, 0, 1, 0.45, ArcOrientation.ArcClockwise);
  EllipticArcSegment ellipse = eabElp.ToSegment();

  //Set symbolology, create and add element to layout
  CIMStroke outline = SymbolFactory.Instance.ConstructStroke(ColorFactory.Instance.GreenRGB, 2.0, SimpleLineStyle.Dot);
  CIMPolygonSymbol ellipseSym = SymbolFactory.Instance.ConstructPolygonSymbol(ColorFactory.Instance.GreyRGB, SimpleFillStyle.Vertical, outline);
  //At 2.x - GraphicElement elpElm = LayoutElementFactory.Instance.CreateEllipseGraphicElement(layout, ellipse, ellipseSym);
  //         elpElm.SetName("New Ellipse");

  var polyLine = PolylineBuilderEx.CreatePolyline(ellipse);
  GraphicElement elpElm = ElementFactory.Instance.CreateGraphicElement(layout, polyLine, ellipseSym, "New Ellipse");
});

//Must be on QueuedTask.Run(() => { ...

//Build geometry
Coordinate2D center = new Coordinate2D(4.5, 4);
var eabCir = new EllipticArcBuilderEx(center, 0.5, ArcOrientation.ArcClockwise);
var cir = eabCir.ToSegment();

var poly = PolygonBuilderEx.CreatePolygon(
  PolylineBuilderEx.CreatePolyline(cir, AttributeFlags.AllAttributes));

//Set symbolology, create and add element to layout
CIMTextSymbol sym = SymbolFactory.Instance.ConstructTextSymbol(
                ColorFactory.Instance.GreenRGB, 10, "Arial", "Regular");
string text = "Circle, circle, circle";

GraphicElement cirTxtElm = ElementFactory.Instance.CreateTextGraphicElement(
  container, TextType.CircleParagraph, poly, sym, text, "New Circle Text", false);

//Must be on QueuedTask.Run(() => { ...

//Build geometry
Coordinate2D center = new Coordinate2D(4.5, 2.75);
var eabElp = new EllipticArcBuilderEx(center, 0, 1, 0.45, ArcOrientation.ArcClockwise);
var ellipse = eabElp.ToSegment();

var poly = PolygonBuilderEx.CreatePolygon(
  PolylineBuilderEx.CreatePolyline(ellipse, AttributeFlags.AllAttributes));

//Set symbolology, create and add element to layout
CIMTextSymbol sym = SymbolFactory.Instance.ConstructTextSymbol(
                      ColorFactory.Instance.BlueRGB, 10, "Arial", "Regular");
string text = "Ellipse, ellipse, ellipse";

GraphicElement ge = ElementFactory.Instance.CreateTextGraphicElement(
  container, TextType.PolygonParagraph, poly, sym, text, "New Ellipse Text", false);