Answer: 160mi
Explanation:
To find the area of a rectangle or that kind of shape u need to find the height and width and that would be 8mi and 20mi and of course they're the same on both side so u need to Height x Width so 8x20=160 or 20+20+20+20+20+20+20+20=160 or 8+8+8+8+8+8+8+8+8+8+8+8+8+8+8+8+8+8+8+8=160 but nobody wants to do it that way unless they absolutely have too