triangle is kirolki

kirolki = triangle (shape) (noun) (some things Google found for "kirolki": a very rare term; user names; appears on a number of Polish websites; in Basque similar kirol means sport; in Finnish somewhat similar kirota means to curse, swear)

Word derivation for "triangle" :
Basque = hiruki, Finnish = kolmio
Miresua = kirolki

Another Basque word for triangle is triangelu.

Both the Basque word and the Finnish word appear to be derived from their language's word for three. (Three in Basque is hiru, three in Finnish is kolme.) My Miresua word for triangle somewhat resembles the Miresua word for three, kire.

The word triangle doesn't occur in Alice's Adventures in Wonderland or Through the Looking-glass.