Engineers have been structually calculating for the curvature of the earth since the dawn of time.

If the earth was flat, many of their structures would have failed quickly.

Why do so many people struggle with flat earth theories?

Okay, genius, using geometry to prove an arc, if the earth is round, as you believe, show us where you have observed the earth curving at the rate of 8 inches, times miles squared.
When you observe a ship disappearing "over the curvature," try picking up a pair of binoculars, and if you see it, again, you're just now discovering "perspective" that you always mistook for "curvature."
The following photo is incompatible with your ball earth Belief.

when I discovered this along time ago, that brought me to the conclusion that we were created by God, The Most High and we live in a Creation. this is when I became born-again. I KNEW God existed after this discovery. I had to relearn literally everything. I told myself I wouldn't believe ANYTHING and I would start over. I get a lot of shit for my beliefs but I am much closer to the Good Lord now. All glory to The Most High! We were created. Its a beautiful revelation when you discover it on your own.