[techfreak125]

On a flat earth, parallax can still be used to determine the distance to celestial objects. However, the observer baseline distance will not be the chord length but the distance between two points on a flat earth. Using hypothetical simulations, I have concluded that the moon must be 377585 km instead of 4800 km! Isn't that higher than the supposed dome? Why would the moon be higher than the sun in the flat earth model?

[ShootingStar]

That's a pretty good estimate for the Moon distance. Actual distance is 384,400km. Can't comment on your other two questions as I don't really know what their (FE'ers) models say. I don't think they do either if the truth be told. Depends on the lottery numbers.

What I can tell you is that the Moon is 400 times nearer than the Sun but also 400 times smaller.  That is why they appear the same size in the sky.

[techfreak125]

Isn't that wonderful? The formula for angular diameter allows us to use the distances to the sun and moon and their respective diameters to find their apparent size!

[ShootingStar]

Yep.  The mean angular diameter for the Sun and Moon is just over half a degree (32') so if you know the size differences you can work out the differences in distance or vice versa. Over the years these have been calculated to a high degree of accuracy.  Consistency in results indicates a correct answer!

The fact that FE models seem to produce significantly difference estimates of the distance of the Moon and Sun is a sure sign that something is amiss there.