Where does “тригуна” come from?

тригуна (Bulgarian) comes from Greek τρίγωνο, from Ancient Greek τρίγωνον, from Ancient Greek τρίγωνος, from Ancient Greek γωνία, from Ancient Greek γόνυ, from Proto-Hellenic gónu, from Proto-Indo-European ǵónu — knee.

тригуна (Bulgarian): a triangular pastry made of puff pastry, typically filled with nuts or cream and soaked in sugar syrup

Definitions

a triangular pastry made of puff pastry, typically filled with nuts or cream and soaked in sugar syrup

Ancestry of “тригуна”, step by step

Step	Language	Word	Meaning
1	Greek	τρίγωνο	triangle
2	Ancient Greek	τρίγωνον	triangle; one of the Athenian lawcourts; the...
3	Ancient Greek	τρίγωνος	three-cornered; three-sided
4	Ancient Greek	γωνία	corner, angle; joiner's square; cornerstone
5	Ancient Greek	γόνυ	knee
6	Proto-Hellenic	gónu	knee
7	Proto-Indo-European	ǵónu	knee

Every word from Proto-Indo-European ǵónu →Every word from Proto-Hellenic gónu →Every word from Ancient Greek γόνυ →