Radio device communication and triangulation?

Yes, you set-up receiver and listen to the transmission. I worked at a college radio station, we would have on our headphones and listen to the station on radio not on the “board out”

Technically, GPS qualifies. GPS operates by communicating with multiple satellites and comparing the signals (actually timestamps sent from an atomic clock) in order to get your location based ion the difference between those times. GPS requires a minimum of four signals to work with the sort of accuracy we expect, but the way the 32 GPS satellites orbit, there are usually 9 available in any given location at any given time though, so it’s usually not hard to get 4 signals.

In a pinch, only having 2 signals would get you in the ballpark; about as close as non-GPS radio triangulation.

Just to be clear, Are you are asking if it is possible to see if people are listening to your transmitted radio signal?
I will give you two answers. “Normal’ equipment cannot detect it. Receiving radios are passive But actually “special” equipment can detect it. It listens for the IF stage of the receiving radio and sniffs for a beat when a certain tone or known signal is transmitted.
Canadian police have had radar detector detectors for years that used this method to find illegal radar detectors in American cars.

Before GPS, there were radio navigation beacons around the world for aircraft and seacraft. The system was called LORAN. The receiver would calculate your position using signals from two transmitters.

I had friends with 30— to 50-foot sailboats and they used LORAN for long trips.