I used to have to do a lot of geometry when I did CNC work. Not so much these days though. Now it's all superheat and subcool calculations or static pressures and air volume and shit like that.
Well I guess there's still a little bit of geometry. Like today, I only had a 4 3/4" holesaw but I needed to make a 5" inch hole through the side of a house. So I needed to make the hole bigger with the sawzall but I had to make it line up perfectly with the one I'd drilled and cut above it so when I shoved the 5" cylinder inside the circularish hole the square on the end of the cylinder was perfectly lined up with the square on the end of the other cylinder. See look at all those shapes and shit. Fucking geometry.