public CIMColor BlackRGB {get;}

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

//Build geometry
List<Coordinate2D> plCoords = new List<Coordinate2D>();
plCoords.Add(new Coordinate2D(1.5, 10.5));
plCoords.Add(new Coordinate2D(1.25, 9.5));
plCoords.Add(new Coordinate2D(1, 10.5));
plCoords.Add(new Coordinate2D(0.75, 9.5));
plCoords.Add(new Coordinate2D(0.5, 10.5));
plCoords.Add(new Coordinate2D(0.5, 1));
plCoords.Add(new Coordinate2D(0.75, 2));
plCoords.Add(new Coordinate2D(1, 1));
Polyline linePl = PolylineBuilderEx.CreatePolyline(plCoords);

//Set symbology, create and add element to layout
CIMLineSymbol lineSym = SymbolFactory.Instance.ConstructLineSymbol(
          ColorFactory.Instance.BlackRGB, 2.0, SimpleLineStyle.Solid);
//var graphic = GraphicFactory.Instance.CreateShapeGraphic(linePl, lineSym);

var ge = ElementFactory.Instance.CreateGraphicElement(
                        container, linePl, lineSym, "New Freehand");

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

List<Coordinate2D> plyCoords = new List<Coordinate2D>();
plyCoords.Add(new Coordinate2D(1, 1));
plyCoords.Add(new Coordinate2D(1.25, 2));
plyCoords.Add(new Coordinate2D(1.5, 1.1));
plyCoords.Add(new Coordinate2D(1.75, 2));
plyCoords.Add(new Coordinate2D(2, 1.1));
plyCoords.Add(new Coordinate2D(2.25, 2));
plyCoords.Add(new Coordinate2D(2.5, 1.1));
plyCoords.Add(new Coordinate2D(2.75, 2));
plyCoords.Add(new Coordinate2D(3, 1));
Polygon poly = PolygonBuilderEx.CreatePolygon(plyCoords);

//Set symbology, create and add element to layout
CIMStroke outline = SymbolFactory.Instance.ConstructStroke(
            ColorFactory.Instance.BlackRGB, 2.0, SimpleLineStyle.Solid);
CIMPolygonSymbol polySym = SymbolFactory.Instance.ConstructPolygonSymbol(
         ColorFactory.Instance.RedRGB, SimpleFillStyle.ForwardDiagonal, outline);

ElementFactory.Instance.CreateGraphicElement(
  container, poly, polySym, "New Lasso");