usually its used to find a missing angle or length of a right triangle. Of course there is more to trigonometry. any way you can use sine, cosine, and tangent, to fine the missing angle or length
Generally pre-calculus is taken after trigonometry, unless the trigonometry course was supplemented by a pre-calculus course, in which case the next course would be calculus.
History of trigonometry.The history of trigonometry dates back to the early ages of Egypt and Babylon. Angles were then measured in degrees. History of trigonometry was then advanced by the Greek...