Where does “fire triangle” come from?

fire triangle (English) comes from English fire, from Middle English fier, from Old English fȳr, from Old English feor, from Proto-Germanic ferrai, from Proto-Indo-European per-nóy, from Proto-Indo-European per-, from Proto-Indo-European pr̥tós — passed , crossed.

fire triangle (English): The three elements necessary and sufficient to sustain a fire: fuel (e.g. wood or petrol/gasoline), oxidizer (e.g. oxygen), and sufficient heat (e.g. reaction temperature or activation energy)

Definitions

  1. The three elements necessary and sufficient to sustain a fire: fuel (e.g. wood or petrol/gasoline), oxidizer (e.g. oxygen), and sufficient heat (e.g. reaction temperature or activation energy)

Ancestry of “fire triangle”, step by step

fire triangle traces back through two separate lines of ancestry.

via English fire

StepLanguageWordMeaning
1EnglishfireA chemical reaction involving the bonding of...
2Middle EnglishfierAlternative form of figer
3Old Englishfȳrfire
4Old EnglishfeorAlternative form of feorr; far
5Proto-Germanicferraifar, distant
6Proto-Indo-Europeanper-nóy
7Proto-Indo-Europeanper-before, in front; first; to go through
8Proto-Indo-Europeanpr̥tóspassed , crossed

via English triangle

StepLanguageWordMeaning
1EnglishtriangleA polygon with three sides and three angles; A...
2Middle Englishtriangle
3Old Frenchtriangle
4Latintriangulumtriangle; nominative neuter singular of...
5Latintriangulustriangular, three-cornered, three-sided;...
6LatinAngulusA city of the Vestini, situated on a hill near the Adriatic Sea, now the town of Città Sant'Angelo
7Proto-Indo-Europeanh₂engulosjoint?
8Proto-Indo-Europeanh₂eng-curve, bend
Every word from Proto-Indo-European pr̥tós