The above doesn't work — it's Ground on Electric rather than Rock on Electric. Now Rock > Flying > Ice would work (notwithstanding that Ice attacks will do normal damage to a Rock Pokémon).
Bug > Grass > Rock
Dark > Psychic > Fighting
Electric > Water > Ground
Fire > Grass > Ground
Fire > Grass > Water
Fire > Ice > Ground
Fighting > Rock > Flying
Fighting > Ice > Flying
Flying > Grass > Rock
Grass > Ground > Poison
Grass > Rock > Ice
Ground > Rock > Ice
Ground > Steel > Ice
Some of these would make excellent starter Poke suggestions for the upcoming DP version. We will probably be subjected to yet another round of the lame/overplayed Water/Grass/Fire, but just think of the possibilities these triangles could create.
Fighting > Rock > Flying is the best one because they all have resistances and weaknesses to each other, have no immunities, and are all physical types (just like Fire > Grass > Water have are all special types).