Southern Triangle vs Triangulum Australe

Southern Triangle and Triangulum Australe both are nouns.

Word	Noun	Adjective	Verb	Adverb
Southern Triangle	Yes	No	No	No
Triangulum Australe	Yes	No	No	No

As nouns, Southern Triangle and Triangulum Australe are synonyms defined as:

Southern Triangle and Triangulum Australe: a small bright constellation in the polar region of the Southern Hemisphere near Circinus and Apus

Southern Triangle (noun)	Triangulum Australe (noun)
a small bright constellation in the polar region of the Southern Hemisphere near Circinus and Apus	a small bright constellation in the polar region of the Southern Hemisphere near Circinus and Apus