public EllipticArcBuilderEx( 
   EllipticArcSegment ellipticArc,
   SpatialReference spatialReference
)

// retrieve the curve's properties
EllipticArcBuilderEx builder = new EllipticArcBuilderEx(arcSegment);
MapPoint startPt = builder.StartPoint;
MapPoint endPt = builder.EndPoint;
Coordinate2D centerPt = builder.CenterPoint;
bool isCircular = builder.IsCircular;
bool isMinor = builder.IsMinor;
double startAngle = builder.StartAngle;
double endAngle = builder.EndAngle;
double centralAngle = builder.CentralAngle;
double rotationAngle = builder.RotationAngle;
ArcOrientation orientation = builder.Orientation;

//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);