geo_polygon "lat1,long1 : lat2,long2 : lat3,long3"
Note the use of the commas and colons. Inside the double quotes, you have a colon-seperated list of latitude-longitude pairs. The latitude and longitude are separated by commas.
The polygon points should be in the correct order so as to form an outline around your bounded area. They must be presented in a sequence that represents a clockwise or counter-clockwise walk around the polygon.
Spaces and new lines in the argument are ignored.
1. Filter for content originating inside a polygon.
To filter for content originating from geographical locations defined by a polygon with up to 32 vertices.