[Visual Basic 6.0]
The example shows how to get the Geometry properties for a selected polygon in an ArcMap edit session.
 Public Sub t_IGeometry_polygon()
   Dim pID As New UID
   pID = "esriEditor.editor"
   Dim pEditor As IEditor
   Dim pApp As IApplication
   Set pApp = Application
   Set pEditor = pApp.FindExtensionByCLSID(pID)
   
   If pEditor.SelectionCount <>  1 Then
     MsgBox "select one polygon"
     Exit Sub
   End If
   
   Dim pEnumFeat As IEnumFeature
   Dim pFeature As IFeature
 
   Set pEnumFeat = pEditor.EditSelection
 
   Dim pGeometry As IGeometry
 
   Set pFeature = pEnumFeat.Next
 
   While Not pFeature Is Nothing
     If pFeature.Shape.GeometryType = esriGeometryPolygon Then
       Set pGeometry = pFeature.Shape
       MsgBox "+++Polygon::IGeometry properties..." & vbCrLf _
         & "Dimension = " & pGeometry.Dimension & vbCrLf _
         & "Geometry type = " & pGeometry.GeometryType & vbCrLf _
         & "Envelope =  " & pGeometry.Envelope.XMin & "," & pGeometry.Envelope.YMin & "," _
         & pGeometry.Envelope.XMax & "," & pGeometry.Envelope.YMin & vbCrLf _
         & "IsEmpty =  " & pGeometry.IsEmpty & vbCrLf _
         & "SpatialReference = " & pGeometry.SpatialReference.Name
     End If
     Set pFeature = pEnumFeat.Next
   Wend
 
 End Sub

[C#]
// The example shows how to get the properties for a selected polygon in
  // an ArcMap edit session.
  public void ShowPolygonProperties()
  {
    //get editor extension
    UID editorUID = new UIDClass();
    editorUID.Value = "esriEditor.Editor";
    IEditor editor = m_application.FindExtensionByCLSID(editorUID) as IEditor;
    if (editor.SelectionCount != 1)
    {
      System.Windows.Forms.MessageBox.Show("Start Editor and select one polygon");
      return;
    }
    IEnumFeature selectedFeatures = editor.EditSelection;
    IPoint centerPoint = new PointClass();
    IPoint labelPoint = new PointClass();
    IFeature feature = selectedFeatures.Next();
    while (feature != null)
    {
      if (feature.Shape.GeometryType == esriGeometryType.esriGeometryPolygon)
      {
        IArea area = feature.Shape as IArea;
        String message = "+++Polygon.IArea properties...\n" +
                         "Area = " + area.Area + "\n" +
                         "Center.X = " + area.Centroid.X + "\n" +
                         "Center.Y = " + area.Centroid.Y + "\n" +
                         "LabelPoint.X = " + area.LabelPoint.X + "\n" +
                         "LabelPoint.Y = " + area.LabelPoint.Y;
        area.QueryCentroid(centerPoint);
        area.QueryLabelPoint(labelPoint);
        message = message + "\n" + "+++Polygon.IArea Queries..." + "\n" +
                            "Center = " + centerPoint.X + "," + centerPoint.Y + "\n" +
                            "Label = " + labelPoint.X + "," + labelPoint.Y;
        System.Windows.Forms.MessageBox.Show(message);
      }
      feature = selectedFeatures.Next();
    }
  }

[Visual Basic .NET, C++]
No example is available for Visual Basic .NET or C++. To view a Visual Basic 6.0 or C# example, click the Language Filter button in the upper-left corner of the page.