Latest Contributions by DanielLaidlaw

See the IConstructCircularArc interface for the built-in ArcObjects methods. ... View more

You can get the extent of the feature class from IGeoDataset.Extent.  See the developer help for more info on what the envelope it returns actually is. ... View more

Try the IPolygon4::ExteriorRingBag Dim pPolygon As ESRI.ArcGIS.Geometry.IPolygon4 = pPolygonGeometry Dim pGeoBag As ESRI.ArcGIS.Geometry.IGeometryBag = pPolygon.ExteriorRingBag Dim pGeoCollection As ESRI.ArcGIS.Geometry.IGeometryCollection = pGeoBag MsgBox(pGeoCollection.GeometryCount) ... View more

An obtuse triangle is a triangle in which one of the angles is an obtuse angle. The returned angle is the smaller angle formed by an imaginary line from the first to the second point and the second to the third point. Therefore, you may need to check all three angles to decide. The measure of the constructed angle is between -Pi and Pi. The conversion from is correct. Should I just multiply by 180/pi  to convert from radians to degrees and see if its greater than 90 degrees?? ... View more

No.  The order of the points in the point collection match the order in which they appear in the polyline or polygon that they represent.  For a polygon, outer rings will have points ordered clockwise and interior rings will have points ordered counter-clockwise. ... View more

Dan, Personally I would have used the IConstructCircularArc interface and the method ConstructCircle but as always there are several ways to do things. You can then Cut the circle with ITopologicalOperator using the Cut method. You will need to create a pointer of type IPolyline to the circle geometry. Duncan ... View more

You could always use the Parallelogram law disussed in wikipedia here ? ... View more

It seems your are using ArcObjects and not the WPF SDK. You might get better answers by posting your question on this forum . ... View more

using featureCursor.NextFeature() in a loop will retrieve all the features. Use ITopologicalOperator.ConstructUnion method to merge the geometries. IGeometryCollection unionCol = new GeometryBag() as IGeometryCollection; ITopologicalOperator unionPoly = new PolygonClass() as ITopologicalOperator; object Missing = Type.Missing; IFeature pFeature = featureCursor.NextFeature(); while(pFeature!=null) {     IGeometry pGeometry = pFeature.Shape;     unionCol.AddGeometry(pGeometry , ref Missing, ref Missing);     pFeature = featureCursor.NextFeature(); } unionPoly.ConstructUnion((IEnumGeometry)unionCol); ... View more