Both Bing and Google Maps have drawing tools that you can use to define an area for a technician. The tools behaving a little differently from each other, as well as with different browsers, but once you have drawn the shape, the Schedule will behave the same.
Using Bing Maps
Use the Bing Maps polygon drawing tool 
located at the top left of the Map View to draw a shape on the map.
Adding a shape
- Click the drawing tool and then click once on the map.
- You now have a line that will follow your mouse on the map.
- Click another location on the map to view a straight line.
- As you move your mouse a shape appears on the map.
- Click on the map again with your mouse to create an endpoint.
- You can add as many endpoints as you'd like by clicking in other areas on the map.
- On the final endpoint, double-click with your mouse.
Editing a shape
The shape that you've created can be edited by clicking and dragging the circles (or handles) that display on each corner and mid-line of the shape.
Deleting a shape
You can delete a shape by clicking the eraser 
icon that displays next to the drawing tool or you can use the Escape (ESC) key on your keyboard.
Not all browsers work the same. For example, in Firefox you may have to click inside the shape and then press the ESC key on your keyboard. Additionally, if you are using Chrome and want to delete the shape, Schedule may display a message regarding adding appointments to the route. Choose No to close the message and the shape disappears.