Currently the Bing Maps App SDK .chm documentation covers how to add Pushpins on the map, but not polylines and polygons.  When creating your entities, rather than passing in a PointPrimitive instance to the Entity.Primitive property, you can pass in a PolylinePrimitive or a PolygonPrimitive instance instead.  The constructor for PoylinePrimitive and PolygonPrimitive takes in a collection of locations, and a Brush instance to indicate the line color/polygon fill.  The following example adds a Polyline to a map (assumes your Map/Layers/Entities are registered correctly as per the SDK):

                Location point1 = new Location(0, 0);
                Location point2 = new Location(0, 50);
                Location point3 = new Location(-25, 25);

                LocationCollection locationCollection = new LocationCollection();
                locationCollection.Add(point1);
                locationCollection.Add(point2);
                locationCollection.Add(point3);

                SolidColorBrush mySolidColorBrush = new SolidColorBrush();
                mySolidColorBrush.Color = Color.FromArgb(255, 0, 0, 255);

                PolylinePrimitive polyline = new PolylinePrimitive(locationCollection, mySolidColorBrush);

                // Assume Entity instance exists and we will be adding it to our Map Layer
                entity.Primitive = polyline;

Figure 1.0 – Adding a polyline to the Bing Maps App, viewed through the Map App Test Tool

The following sample adds a polygon in the same location.  Note that the only real difference is that we are passing in a PolygonPrimitive type and it’s constructor takes a third Brush parameter to represent the fill:

                Location point1 = new Location(0, 0);
               
Location point2 = new Location(0, 50);
                Location
point3 = new Location(-25, 25);

               
LocationCollection locationCollection = new LocationCollection();
               
locationCollection.Add(point1);
               
locationCollection.Add(point2);
               
locationCollection.Add(point3);

                SolidColorBrush
mySolidColorBrush = new SolidColorBrush();
               
mySolidColorBrush.Color = Color.FromArgb(255, 0, 0, 255);

                PolygonPrimitive
polygon = new PolygonPrimitive(locationCollection, mySolidColorBrush,mySolidColorBrush);

               
// Assume Entity instance exists and we will be adding it to our Map
Layer
                entity.Primitive = polygon;

Figure 2.0 – Adding a polygon to the Bing Maps App, viewed through the
Map App Test Tool