Find the perimeter of a square is each side is 3/4 miles long

Three miles long

Since a square has four equal sides and perimeter is just the lengths of all sides of a shape added together, we would add 3/4 to itself four times or can multiply it by 4.

One way: 3/4 + 3/4 + 3/4 + 3/4= 12/4 = 3

Another way: 4 x (3/4)= 3

Either way it's the same process and the answer is that the perimeter is 3 miles long.