There is 43,560 sq ft in a acre, there is , a sq mile is 5,280 ft. X 5,280 FT. So that makes 1,214,383,104,000 sq ft in a sq mile. Divided that by the sq ft in a acre and you have 640 acres in a sq mile
There are 640 acres in a square mile. If you ask how many acres are in .17 square miles the the answer would be 640X 0.17 = 108.8 acres.
640 acres are in an mile