the word trigonometry comes from the greek word "trigono" (triangle) and "metro" (count) which quite clearly describe what trigonometry covers: counting triangl

the word trigonometry comes from the greek word "trigono" (triangle) and "metro" (count) which quite clearly describe what trigonometry covers: counting triangles (ie sides and angles). Its history dates back to at least the ancient greeks (if not more/other civilizations, I do not know). Linear algebra is a different field of mathematics which focuses on solving systems of linear equations which has a LOT of applications (even in other non applied mathematics). I think it is better if you do not try to think one as part of the other. trigonometry provides the trigonometric functions, their relationship and a few basic equations. Linear algebra provides vectors/matrices. You need both of them to model 3D objects and vectors interscting with them (aka rays hitting objects)