ArcGIS Pro 2.6 API Reference Guide
QueryCoords Method (EllipticArcSegment)
Example 

ArcGIS.Core.Geometry Namespace > EllipticArcSegment Class : QueryCoords Method
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 length of the semi-minor axis.
Copies the center coordinate, start angle, central angle, rotation angle, semi-major/semi-minor axes into the method parameters.
Syntax
Public Sub QueryCoords( _
   ByRef centerCoordinate As Coordinate2D, _
   ByRef startAngle As Double, _
   ByRef centralAngle As Double, _
   ByRef rotationAngle As Double, _
   ByRef semiMajorAxis As Double, _
   ByRef semiMinorAxis As Double _
) 

Parameters

centerCoordinate
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.
semiMinorAxis
The length of the semi-minor axis.
Remarks
Angles are in radians.
Example
// retrieve the curve's control points
EllipticArcSegment arc = EllipticArcBuilder.CreateEllipticArcSegment(arcSegment);
MapPoint startPt = arc.StartPoint;
MapPoint endPt = arc.EndPoint;
Coordinate2D centerPt = arc.CenterPoint;
bool isCircular = arc.IsCircular;
bool isMinor = arc.IsMinor;
bool isCounterClockwise = arc.IsCounterClockwise;
bool isCurve = arc.IsCurve;
double len = arc.Length;
double ratio = arc.MinorMajorRatio;

double semiMajorAxis, semiMinorAxis;
// get the axes
arc.GetAxes(out semiMajorAxis, out semiMinorAxis);
// or use the properties
// semiMajorAxis = arc.SemiMajorAxis;
// semiMinorAxis = arc.SemiMinorAxis;

double startAngle, centralAngle, rotationAngle;
// or use QueryCoords to get complete information
arc.QueryCoords(out centerPt, out startAngle, out centralAngle, out rotationAngle, out semiMajorAxis, out semiMinorAxis);

// use properties to get angle information
//double endAngle = arc.EndAngle;
//centralAngle = arc.CentralAngle;
//rotationAngle = arc.RotationAngle;
//startAngle = arc.StartAngle;
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

EllipticArcSegment Class
EllipticArcSegment Members