What do Phil Jackson and the US Government have in common? They both utilized systems called "The Triangle" that are now obsolete.
Phil Jackson is a former 11x Champion NBA basketball coach and former president and GM for the New York Knicks, and creator of the "Triangle Offense". The Triangle style offense in basketball is now obsolete because it never real was much to begin with. Think Phil Jackson won 11 Championships as a coach because of his system or because he happened to be coaching some of best basketball players to ever live (Jordan, Pippen, Kobe, Shaq, etc.)? I'm going to go with the latter. The Triangle sure didn't work in New York, despite his persistence.
The Triangle that is being referred to in relation to the US Government is that of Triangulation Stations. In other words, these stations were essentially the primary way that distances were measured and infrastructures were configured. They're obsolete today due to GPS technology, which brings us full circle: Geocaching -- brought to you by GPS technology!
The cache is located near the Triangulation Station.