ArcGIS Pro 2.7 API Reference Guide
EllipticArcBuilder Constructor(MapPoint,Double,Double,Double,esriArcOrientation,MinorOrMajor,SpatialReference)
Example 

ArcGIS.Core.Geometry Namespace > EllipticArcBuilder Class > EllipticArcBuilder Constructor : EllipticArcBuilder Constructor(MapPoint,Double,Double,Double,esriArcOrientation,MinorOrMajor,SpatialReference)
The point from which the arc starts.
The length of the chord connecting start point to the end point of the arc.
The angle in radians of the chord connecting the start point to the end point of the arc.
The radius of the embedded circle.
The orientation of the arc, clockwise or counterclockwise.
Indicates whether the arc is a minor or major arc. A minor arc is an arc such that the central angle is less than PI radians.
(Optional) The spatial reference of the arc. The default value is null.
Builds a new instance of the EllipticArcBuilder class. The new instance will be a circular arc. This method must be called on the MCT. Use QueuedTask.Run.
Syntax

Parameters

startPt
The point from which the arc starts.
chordLength
The length of the chord connecting start point to the end point of the arc.
chordBearing
The angle in radians of the chord connecting the start point to the end point of the arc.
radius
The radius of the embedded circle.
orientation
The orientation of the arc, clockwise or counterclockwise.
minorOrMajor
Indicates whether the arc is a minor or major arc. A minor arc is an arc such that the central angle is less than PI radians.
spatialReference
(Optional) The spatial reference of the arc. The default value is null.
Exceptions
ExceptionDescription
This method or property must be called within the lambda passed to QueuedTask.Run.
Incompatible spatial references.
startPt is null.
Example
// 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 builder convenience method or use a builder constructor.

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

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

// Builder constructors need to run on the MCT.
ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
{
  using (EllipticArcBuilder cab = new EllipticArcBuilder(fromPt, chordLength, chordBearing, radius, orientation, minorOrMajor))
  {
    // do something with the builder

    EllipticArcSegment anotherCircularArc = cab.ToSegment();
  }
});
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

EllipticArcBuilder Class
EllipticArcBuilder Members
Overload List