Creating a polygon in a google map is not really a big deal, basically you are creating a set of locations and storing them GEOJson which it contains all the informaiton we need to draw the graphic poligon in the map. Now, as part of a business process maybe you wanna check if a couple of polygons interects each other in the same location, it can be usefull in orther to handle groups and zones.
For this sample, wi will use a very short script that at least will identify this intersections
the final result is something like this:
And you can try it in this DEMO page: Try it