ArcGIS Pro 2.7 API Reference Guide
EllipticArcBuilder Constructor(Coordinate2D,Double,Double,Double,Double,Double,SpatialReference)
Example 

ArcGIS.Core.Geometry Namespace > EllipticArcBuilder Class > EllipticArcBuilder Constructor : EllipticArcBuilder Constructor(Coordinate2D,Double,Double,Double,Double,Double,SpatialReference)
The center point of the ellipse.
The start angle in radians measured from the rotated x-axis.
The central angle in radians measuring the span of the arc from startAngle to endAngle. A positive value corresponds to counterclockwise orientation.
The angle in radians by which the ellipse is rotated from the x-axis. A positive value corresponds to counterclockwise rotation.
The length of the semi-major axis.
The ratio of the length of the semi-minor axis to the length of the semi-major axis. Must be < 1.
(Optional) The spatial reference of the arc. The default value is null.
Builds a new instance of the EllipticArcBuilder class. This method must be called on the MCT. Use QueuedTask.Run
Syntax

Parameters

centerPt
The center point of the ellipse.
startAngle
The start angle in radians measured from the rotated x-axis.
centralAngle
The central angle in radians measuring the span of the arc from startAngle to endAngle. A positive value corresponds to counterclockwise orientation.
rotationAngle
The angle in radians by which the ellipse is rotated from the x-axis. A positive value corresponds to counterclockwise rotation.
semiMajorAxis
The length of the semi-major axis.
minorMajorRatio
The ratio of the length of the semi-minor axis to the length of the semi-major axis. Must be < 1.
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.
An elliptic arc construction operation was given invalid axes. The minorMajorRatio should be < 1.
Example
// Construct an elliptic arc centered at (1,1), startAngle = 0, centralAngle = PI/2, 
// rotationAngle = 0, semiMajorAxis = 1, minorMajorRatio = 0.5.
// Use a builder convenience method or use a builder constructor.

Coordinate2D centerPt = new Coordinate2D(1, 1);

// Builder convenience methods don't need to run on the MCT.
EllipticArcSegment circularArc = EllipticArcBuilder.CreateEllipticArcSegment(centerPt, 0, Math.PI / 2, 0, 1, 0.5);

double semiMajor;
double semiMinor;
circularArc.GetAxes(out semiMajor, out semiMinor);
// semiMajor = 1, semiMinor = 0.5

// Builder constructors need to run on the MCT.
ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
{
  using (EllipticArcBuilder cab = new EllipticArcBuilder(centerPt, 0, Math.PI / 2, 0, 1, 0.5))
  {
    // do something with the builder

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

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

EllipticArcBuilder Class
EllipticArcBuilder Members
Overload List