triantánacht

== Irish == === Etymology === From triantán (“triangle”) +‎ -acht. === Noun === triantánacht f (genitive singular triantánachta) (mathematics) trigonometry ==== Declension ==== ==== Derived terms ==== triantánacht phlánach (“plane trigonometry”) ==== Related terms ==== triantánúil (“trigonometrical”, adjective) === Mutation === === Further reading === Ó Dónaill, Niall (1977), “triantánacht”, in Foclóir Gaeilge–Béarla, Dublin: An Gúm, →ISBN “trigonometry”, in New English-Irish Dictionary, Foras na Gaeilge, 2013–2026