Which constellations make up the autumn triangle?

The south triangle of autumnal equinox (also known as the south triangle of autumnal equinox, the south triangle of autumnal equinox or the great triangle of autumnal equinox) is a triangle composed of three bright stars in the southern sky of the northern hemisphere in autumn, namely, Beiluoshimen (1. 16, etc. ), thinking empty (2.04, etc. ) in Pisces and Firebird VI (2.39, etc. ) In Phoenix.