Define a model of incidence geometry with points 1, 2, 3, 4, 5, 6; lines consisting of the sets {1,2,3}, {3,4,5}, {5,6,1}, {1,4}, {2,5}, {3,6}, {2,6}, {4,6}, {2,4}; and lies on meaning is an element of. Which, if any, of the parallel postulates is (are) satisfied by this model? Can you figure out what is remarkable about parallelism in this model?