Revelation 7:1 KJV
And after these things I saw four angels standing on the four corners of the earth, holding the four winds of the earth, that the wind should not blow on the earth, nor on the sea, nor on any tree.
A very dear friend of mine and preacher of fifty years experience recently told me that, based upon verses such as this one, he believed the land mass if the earth, prior to the flood, was square.
Evolutionary scientists believe, just as Christians do, that at one time all of the land was one giant continent. We differ on when and how the continental drift took place but we agree that it did happen. Christians believe it was much more recent than evolutionists and that it was a result of the devastation of the Flood.
The event described in the Bible was much more than a terrible rain storm. The firmament of the heavens broke and poured down rain but so did the ground break open and the waters under the earth burst out upon the ground. Such a cataclysm certainly had the force to break the earth open and tear the continent apart.
A precursory look at a map makes it obvious that the continents, with some pieces lost under the oceans, fit together as a solid, single unit. There is no reason not to think that unit may have been square and that there were literally four corners of the earth at one time.