You can use the google.maps.geometry.poly.containsLocation and google.maps.geometry.spherical.interpolate functions.
for example. get a boundary point and the center point of the polygon and use the function 'google.maps.geometry.spherical.interpolate ({centerpoint}, {bundaypoint}, {distance})' then you verify that the resulting point is in the area of the polygon with 'google.maps.geometry.poly.containsLocation ({resultPoint}, {polygonObject})' function.
GetBounds function:
if (!google.maps.Polygon.prototype.getBounds) {
google.maps.Polygon.prototype.getBounds = function (latLng) {
var bounds = new google.maps.LatLngBounds();
var paths = this.getPaths();
var path;
for (var p = 0; p < paths.getLength() ; p++) {
path = paths.getAt(p);
for (var i = 0; i < path.getLength() ; i++) {
bounds.extend(path.getAt(i));
}
}
return bounds;
}
}