Rango: Cambridge Dictionary of American English
Meaning 3 of the word "corner"
A corner can also be a part or area of a place.
Canadian junior dictionary.(Meaning number-meaning)
7. a secret place; a place away from the crowds:The money was hidden in odd corners of the house
8. a region or part; a place that is far away: People have searched in all corners of the earth for gold.
If u say that the earth is a rectangle, that'll contradict with Isaiah 40:22 "There is one who dwells above the circle of the earth"