Practical Trig

Most all of the trig I have used in real life has been in connection with machine shop production: CNC mill and lathe programming and CAD design.
Nearly all trig problems can be solved with just four formulas:

with hypotenuse known:
OPP = HYP·sin(θ)
ADJ = HYP·cos(θ)

with either leg known
OPP = ADJ·tan(θ)
ADJ = OPP / tan(θ)

CNC mill problems are usually hypotenuse/angle problems (converting bolt patterns to x-y coordinates)
CNC lathe problems are usually leg problems (converting chamfers and tapers to x-z coordinates)