the line graph of the complete graph "k" is also known as the triangular graph, the johnson graph "j"("n",2), or the complement of the kneser graph "kg". triangular graphs are characterized by their spectra, except for "n" = 8. they may also be characterized (again with the exception of "k") as the strongly regular graphs with parameters srg("n"("n" − 1)/2, 2("n" − 2), "n" − 2, 4). the three strongly regular graphs with the same parameters and spectrum as "l"("k") are the chang graphs, which may be obtained by graph switching from "l"("k").