If there were a planet around one of the 3 stars, there woud be several aspects:
If the 2 stars are too close to each other, no planet can orbit just one of them, but the planet would have to orbit both stars. Now, one could wonder if such an orbit can be stable! Can a planet remain there? Or would it be expelled ASAP, not leaving any time for life to evolve.
If the stars are far away from each other, orbiting one of them could become possible.
It's possible Science Fiction has already foreseen such a possibility (RocheWorld - Dragonfly??). But it depends on how far the stars are from each other.

Raoul