How to get shapefile's geometry from local shapefile?

[Brubakerfloors]

I'd like to use GeometryEngine.Contains Method on  polygons from these shapefiles but i can't retrieve polygons . How can I retrieve them? Please Help me.

GeometryEngine.Contains Method 

  List<MapPoint> spatialReferenceExtentCoords = new List<MapPoint>   
          { 
                new MapPoint(-103.070, 31.720, SpatialReferences.Wgs84),
                 new MapPoint(-103.070, 34.580, SpatialReferences.Wgs84),
                 new MapPoint(-94.000, 34.580, SpatialReferences.Wgs84),
                 new MapPoint(-94.00, 31.720, SpatialReferences.Wgs84)
             };             
_spatialReferenceArea = new Polygon(spatialReferenceExtentCoords);//can i get that polygon from my shapefile 
_spatialReferenceArea = GeometryEngine.Project(_spatialReferenceArea, statePlaneNorthCentralTexas) as Polygon;

 Thank You,Everyone.

[RichardWood]

Did you ever get an answer to this? I'm facing the same problem.