public abstract class Geometry 

// methods need to run on the MCT
ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
{
  try
  {
    // open a gdb
    using (ArcGIS.Core.Data.Geodatabase gdb = 
              new ArcGIS.Core.Data.Geodatabase(
                  new FileGeodatabaseConnectionPath(new Uri(@"c:\Temp\MyDatabase.gdb"))))
    {
      //Open a featureClass 
      using (ArcGIS.Core.Data.FeatureClass featureClass = 
                     gdb.OpenDataset<ArcGIS.Core.Data.FeatureClass>("Polygon"))
      {
        
        ArcGIS.Core.Data.QueryFilter filter = 
                   new ArcGIS.Core.Data.QueryFilter()
                    {
                      WhereClause = "OBJECTID = 6"
                    };

        // get the row
        using (ArcGIS.Core.Data.RowCursor rowCursor = 
                               featureClass.Search(filter, false))
        {
          while (rowCursor.MoveNext())
          {
            using (var row = rowCursor.Current)
            {
              long oid = row.GetObjectID();

              // get the shape from the row
              ArcGIS.Core.Data.Feature feature = row as ArcGIS.Core.Data.Feature;
              Polygon polygon = feature.GetShape() as Polygon;

              // do something here
            }
          }
        }
      }
    }
  }
  catch (Exception ex)
  {
    // error - handle appropriately
  }
});