This is trilateration, not triangulation. Triangulation works if you know the angles, trilateration works if you know the distances and uses circles. Source: I

This is trilateration, not triangulation. Triangulation works if you know the angles, trilateration works if you know the distances and uses circles. Source: I've done this before and it is very accurate and creepy. > This could be mitigated by rounding off coordinates to be coarse enough that it doesn't give their precise location before calculating the distance. Reporting a slightly different location to users or varying the search radius per user search could help.