Trig is honestly the math I've used the most since finishing school. But to be fair, that is mostly because it's useful as hell when doing game development as a hobby.
Or building some stairs or really a ton of shit. Basic trig is such a useful thing that it tells me people who complain about it have never built anything, virtual or physical.
as I've said in a different comment , it sucks how little space school gives to recreational usage of the skills we learn . I deeply enjoy recreational linguistics , writing , yet school seldom gave me the tools I find useful , having to find them on my own , despite being thought them previously .