Where does “tasanurkka” come from?

tasanurkka (Finnish) comes from Finnish tasa, from Proto-Finnic tasa, from Proto-Uralic taśa — even.

Ancestry of “tasanurkka”, step by step

tasanurkka traces back through two separate lines of ancestry.

via Finnish tasa

StepLanguageWordMeaning
1Finnishtasaof equal height; of the same level
2Proto-Finnictasaeven
3Proto-Uralictaśaeven

via Finnish nurkka

StepLanguageWordMeaning
1Finnishnurkkacorner
2Proto-Finnicnurkkacorner
Every word from Proto-Uralic taśa →Every word from Proto-Finnic tasa →Every word from Finnish tasa →