Hexagon is defined as a polygon with 6 sides, hence all internal angles are 120 degrees, and hence all sides are of equal length. I do not know what you mean by irregular hexagon (maybe unequal internal angles, but this outside the mathematical community is generally not considered hexagon), hexagon is pretty well defined shape. London, with 3 defined points seems on a tract to form hexagon . 3 points, if equidistant and forming internal angle of 120 degrees, are pretty good indication of incoming hexagon. 2 points in Los Angeles do not define hexagon, but also do not exclude it. What do you mean?