Come on flat earther guy. Yeah, some really fucked up manipulations in education system. But seriously. On my own I designed two solid working models that prove spherical earth.
Simplest. Pick three cities forming a triangle. Using the globe determine the angles between them.
It’s not hard to translate this to what the angles would have to be if flat. Travel. Measure observed angles in real world. You’ll find your measurements match the globe angles, not the flat ones.
Mathematically impossible for world to be flat. Can prove it totally on your own.