public new Envelope ToGeometry()

{
  // Use a builderEx convenience method or use a builderEx constructor.

  MapPoint minPt = MapPointBuilderEx.CreateMapPoint(1.0, 1.0);
  MapPoint maxPt = MapPointBuilderEx.CreateMapPoint(2.0, 2.0);

  Envelope envelope = EnvelopeBuilderEx.CreateEnvelope(minPt, maxPt);

  EnvelopeBuilderEx builderEx = new EnvelopeBuilderEx(minPt, maxPt);
  envelope = builderEx.ToGeometry() as Envelope;
}

{
  // use the convenience builders
  Envelope env1 = EnvelopeBuilderEx.CreateEnvelope(0, 0, 1, 1, SpatialReferences.WGS84);
  Envelope env2 = EnvelopeBuilderEx.CreateEnvelope(0.5, 0.5, 1.5, 1.5, SpatialReferences.WGS84);

  Envelope env3 = env1.Union(env2);

  double area = env3.Area;
  double depth = env3.Depth;
  double height = env3.Height;
  double width = env3.Width;
  double len = env3.Length;

  MapPoint centerPt = env3.Center;
  Coordinate2D coord = env3.CenterCoordinate;

  bool isEmpty = env3.IsEmpty;
  int pointCount = env3.PointCount;

  // coordinates
  //env3.XMin, env3.XMax, env3.YMin, env3.YMax
  //env3.ZMin, env3.ZMax, env3.MMin, env3.MMax

  bool isEqual = env1.IsEqual(env2);    // false

  // or use the builderEx constructors which don't need to run on the MCT.
  EnvelopeBuilderEx builderEx = new EnvelopeBuilderEx(0, 0, 1, 1, SpatialReferences.WGS84);
  builderEx.Union(env2);      // builder is updated to the result

  depth = builderEx.Depth;
  height = builderEx.Height;
  width = builderEx.Width;

  centerPt = builderEx.Center;
  coord = builderEx.CenterCoordinate;

  isEmpty = builderEx.IsEmpty;

  env3 = builderEx.ToGeometry() as Envelope;
}

{
  // use the convenience builders
  Envelope env1 = EnvelopeBuilderEx.CreateEnvelope(0, 0, 1, 1, SpatialReferences.WGS84);
  Envelope env2 = EnvelopeBuilderEx.CreateEnvelope(0.5, 0.5, 1.5, 1.5, SpatialReferences.WGS84);

  bool intersects = env1.Intersects(env2); // true
  Envelope env3 = env1.Intersection(env2);


  // or use the builderEx constructors which don't need to run on the MCT.
  EnvelopeBuilderEx builderEx = new EnvelopeBuilderEx(0, 0, 1, 1, SpatialReferences.WGS84);
  intersects = builderEx.Intersects(env2);
  builderEx.Intersection(env2);   // note this sets the builder to the intersection
  env3 = builderEx.ToGeometry() as Envelope;
}

{
  // Use a builderEx convenience method or use a builderEx constructor.

  // convenience methods don't need to run on the MCT.
  Envelope envelope = EnvelopeBuilderEx.CreateEnvelope(100.0, 100.0, 500.0, 500.0);

  // shrink the envelope by 50%
  Envelope result = envelope.Expand(0.5, 0.5, true);


  // builderEx constructors don't need to run on the MCT.
  EnvelopeBuilderEx builderEx = new EnvelopeBuilderEx(100.0, 100.0, 500.0, 500.0);
  builderEx.Expand(0.5, 0.5, true);
  envelope = builderEx.ToGeometry() as Envelope;
}

{
  Coordinate2D minCoord = new Coordinate2D(1, 3);
  Coordinate2D maxCoord = new Coordinate2D(2, 4);

  Coordinate2D c1 = new Coordinate2D(0, 5);
  Coordinate2D c2 = new Coordinate2D(1, 3);


  // use the EnvelopeBuilderEx.  This constructor doesn't need to run on the MCT.

  EnvelopeBuilderEx builderEx = new EnvelopeBuilderEx(minCoord, maxCoord);
  // builderEx.XMin, YMin, Zmin, MMin  = 1, 3, 0, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 2, 4, 0, double.Nan

  // set XMin.  if XMin > XMax; both XMin and XMax change
  builderEx.XMin = 6;
  // builderEx.XMin, YMin, ZMin, MMin  = 6, 3, 0, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 6, 4, 0, double.Nan

  // set XMax
  builderEx.XMax = 8;
  // builderEx.XMin, YMin, ZMin, MMin  = 6, 3, 0, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 8, 4, 0, double.Nan

  // set XMax.  if XMax < XMin, both XMin and XMax change
  builderEx.XMax = 3;
  // builderEx.XMin, YMin, ZMin, MMin  = 3, 3, 0, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 3, 4, 0, double.Nan

  // set YMin
  builderEx.YMin = 2;
  // builderEx.XMin, YMin, ZMin, MMin  = 3, 2, 0, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 3, 4, 0, double.Nan

  // set ZMin.  if ZMin > ZMax, both ZMin and ZMax change
  builderEx.ZMin = 3;
  // builderEx.XMin, YMin, ZMin, MMin  = 3, 2, 3, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 3, 4, 3, double.Nan

  // set ZMax.  if ZMax < ZMin. both ZMin and ZMax change
  builderEx.ZMax = -1;
  // builderEx.XMin, YMin, ZMin, MMin  = 3, 2, -1, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 3, 4, -1, double.Nan

  builderEx.SetZCoords(8, -5);
  // builderEx.XMin, YMin, ZMin, MMin  = 3, 2, -5, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 3, 4, 8, double.Nan


  builderEx.SetXYCoords(c1, c2);
  // builderEx.XMin, YMin, ZMin, MMin  = 0, 3, -5, double.Nan
  // builderEx.XMax, YMax, ZMax, MMax = 1, 5, 8, double.Nan


  builderEx.HasM = true;
  builderEx.SetMCoords(2, 5);

  var geomEx = builderEx.ToGeometry();
}