Final answer:
One square mile equals 27,878,400 square feet, calculated by squaring the number of feet in one mile (5,280 feet).
Step-by-step explanation:
One square mile is equivalent to 27,878,400 square feet. To find this, we use the fact that one mile measures 5,280 feet long. The area of a square is calculated by squaring the length of its side, so we square the number of feet in a mile:
5,280 feet × 5,280 feet = 27,878,400 square feet
Therefore, option 2) 27,878,400 is the correct answer.