Here's a little nuance for you: Human head don't have corners, but a beard can. We can illustrate this by putting a cheese slice on a kid's ball. The cheese has corners, the ball isn't flat.
Four Corners of the Earth in Context
Every time the phrase the four corners of the earth occurs in the Bible it's in the context of the Millennial Kingdom, which is after the plagues of the tribulation.
The Sons of Noah
The time between Noah's flood and Peleg's tectonics was when the dispersal from Babel took place. From Babel small family groups spread out, figuratively speaking, to the ends of the Earth.
The Four Corners of the Earth
The phrase "the four corners of the earth" occurs a few times in scripture but every time it's in the context of the millennial kingdom, it's never used in any other context.
If you want to believe that earth is flat no one's going to stop you. However nothing in the Bible, either in the meaning of words or in the context of passages, requires you to believe that earth is flat and has an edge.
God's a plan involves us going into eternity in a city which has equal X and Y dimensions, since we've satisfied the requirements of a spherical Earth, we'll model the Millennial Kingdom as foursquare.
Some people believe that the Earth is flat. Some people also believe that the Bible describes a flat Earth. Neither of these are true. The Bible describes a spherical Earth which formed around a gravitational singularity.