Fire Tetrahedron : A four-sided, solid geometric figure that resembles a pyramid, with one of the sides forming the base. Each side indicates one of the four elements required to have fire
Tatyana Davletshina, Industrial Fire Safety Guidebook, Noyes Publications, New Jersey 07675, USA 1998. http://www.aura-o.aura-astronomy.org/aura/sites/de fault/files/files/Referencia_Bibliografica/industr ial%20fire%20protection%20handbook.pdf, (IndFrS - Amer) {470}