I want to know the coordinates of a polyline from specific point and distance. I have attached image to clear the specification. say, I have a points B(2,3). I want to know the coordinates of A and C from 2 feet distance of B point. I have tried this:

public IPoint GetPointAtFrom(double distance, Coordinate givenCoordinate)
        ArcGeometry.IPoint outletPoint = new ArcGeometry.PointClass();
        ArcGeometry.ICurve curve = _polyline;
        curve.QueryPoint(ArcGeometry.esriSegmentExtension.esriExtendTangentAtFrom, distance, false, outletPoint);
        return new Point(outletPoint);

but it gives from point or others.

Any idea? I am using .net in arcgis 10.0


  • What is ArcGeometry? Jan 24, 2016 at 17:46
  • Is measure (M) enabled on your polyline featureclass? Jan 24, 2016 at 18:39

1 Answer 1


One way would be to use ICurve QueryPointAndDistance to and get the DistanceAlongCurve value for your 'B' point.

Then call ICurve.GetSubcurve twice (with the DistanceAlongCurve + 2 and DistanceAlongCurve - 2) and the fromDistance parameter as 0. And the asRatio as false.

The "To" points of the resulting subcurves would be your 'A' and 'C'.



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