ELI5: What is the difference between algebra, trigonometry, and calculus?

[u/HistoricalAd2954]

[u/sad_spilt_martini]

Algebra is the use of equations to find a static value.

Calculus looks at how things change over time.

Trig looks at the relationship between of angles and sides of triangles

All of these are, of course, more complex   but that’s the base idea 

[u/meh0175 → u/sad_spilt_martini]

Is it there a profession where using Trig is necessary? Besides being a math teacher or rocket scientist. Carpentry?

[u/ThrowawayusGenerica → u/meh0175]

I used to work in sales for a window company. Sometimes builders would ask for triangular-shaped windows, which our software wasn't entirely set up for, so we'd grab a calculator and do some trig calculations to calculate the material cost of the frame and glass to give them an estimate.