In other words: If so many planets that were created in different locations and under different circumstances show the same property, it’s likely that our own planet has the same property as well. All of our observations show that other planets are spherical (and since we know how they’re created, it’s also obvious why they take this shape). Unless we have a very good reason to think otherwise (which we don’t), our planet is very likely the same.

72.) Astronomers tell us that, in consequence of the Earth's "rotundity," the perpendicular walls of buildings are, nowhere, parallel, and that even the walls of houses on opposite sides of a street are not! But, since all observation fails to find any evidence of this want of parallelism which theory demands, the idea must be renounced as being absurd and in opposition to all well-known facts. This is a proof that the Earth is not a globe.
On January 25th, 2016 Atlanta rapper B.o.B., who has self-identified as a member of the Flat Earth Society, tweeted a photograph of himself against a skyline, then tweeted a screenshot from Flat Earth Movement literature that proclaimed that Polaris (the North Star) can be seen 20° south of the Equator. Neil DeGrasse Tyson answered the rapper's question, writing "Polaris is gone by 1.5 deg S. Latitude. You’ve never been south of Earth’s Equator, or if so, you've never looked up."
Astronomers are in the habit of considering two points on the Earth's surface, without, it seems, any limit as to the distance that lies between them, as being on a level, and the intervening section, even though it be an ocean, as a vast "hill"-of water!" The Atlantic ocean, in taking this view of the matter, would form a "hill of water" more than a hundred miles high! The idea is simply monstrous, and could only be entertained by scientists whose whole business is made up of materials of the same description: and it certainly requires no argument to deduce, from such "science" as this, a satisfactory proof that the Earth is not a globe.
78) From Anchorage, Alaska at an elevation of 102 feet, on clear days Mount Foraker can be seen with the naked eye 120 miles away. If Earth were a ball 25,000 miles in circumference, Mount Foraker’s 17,400 summit should be leaning back away from the observer covered by 7,719 feet of curved Earth. In reality, however, the entire mountain can be quite easily seen standing straight from base to summit.