The shape of Earth

[sdelsolray]

Premis: We don't know what shape Earth actually is.
...

Learn to speak for yourself, and not for others. Here, read this in front of a mirror:

"Premis (sic): I don't know what shape Earth actually is."

Persuade me, do you know the shape of this realm? 

I choose not to persuade you. I strongly suspect it would be a waste of time. That being said, I am quite satisfied with my understanding of the shape of the Earth. You might consider working on your understanding.

Can you stretch the line across it an measure it for me?

That would not be the best way to measure a three dimensional object. Indeed, it could not be done with a "line".

Regardless of your position, any non-God fearing person should embrace the challenge of proving their knowledge of something as foundational as the ground we stand upon.

Your ignorance, feigned or real, is not a challenge, at least to me. There is nothing to embrace.