right triangle vs triangle

right triangle and triangle both are nouns.

Word	Noun	Adjective	Verb	Adverb
right triangle	Yes	No	No	No
triangle	Yes	No	No	No

As nouns, triangle is a hypernym of right triangle; that is, triangle is a word with a broader meaning than right triangle:

Other hypernyms of right triangle include trigon, trilateral.

right triangle (noun)	triangle (noun)
a triangle with one right angle	a percussion instrument consisting of a metal bar bent in the shape of an open triangle
	any of various triangular drafting instruments used to draw straight lines at specified angles
	a three-sided polygon
	something approximating the shape of a triangle