MapPoint startPoint = MapPointBuilderEx.CreateMapPoint(0, 0);
double tangentDirection = Math.PI / 6;
ArcOrientation orientation = ArcOrientation.ArcCounterClockwise;
double startRadius = double.PositiveInfinity;
double endRadius = 0.2;
ClothoidCreateMethod createMethod = ClothoidCreateMethod.ByAngle;
double angle = Math.PI / 2;
CurveDensifyMethod densifyMethod = CurveDensifyMethod.ByLength;
double densifyParameter = 0.1;
Polyline polyline = PolylineBuilderEx.CreatePolyline(startPoint, tangentDirection, startRadius, endRadius, orientation, createMethod, angle, densifyMethod, densifyParameter, SpatialReferences.WGS84);
int numPoints = polyline.PointCount;
MapPoint queryPoint = polyline.Points[numPoints - 2];
MapPoint pointOnPath;
double radiusCalculated, tangentDirectionCalculated, lengthCalculated, angleCalculated;
PolylineBuilderEx.QueryClothoidParameters(queryPoint, startPoint, tangentDirection, startRadius, endRadius, orientation, createMethod, angle, out pointOnPath, out radiusCalculated, out tangentDirectionCalculated, out lengthCalculated, out angleCalculated, SpatialReferences.WGS84);