⊿ From Wikipedia the free encyclopedia Look up ⊿ in Wiktionary, the free dictionary. ⊿ may refer to: Right triangle, a triangle containing a right angle Triangle (Perfume album), the third album of techno-pop group Perfume Topics referred to by the same term This disambiguation page lists articles associated with the title ⊿.If an internal link led you here, you may wish to change the link to point directly to the intended article.