Question 1078099
So you may be in a box, but you are walking on a square. The area of the square is 16. Since the area is S^2, how do you "undo" the square? The square of a number is found by multiplying the number times itself. How about with the square root? the square root "un-do" the square.
What number times itself equals 16? 1x1, 2x2, 3x3, 4x4
Once you have found that number, that is how far they walked from one corner to the next one.
Now, if you meant from one corner to the OPPOSITE corner it would be a different calculation. If this is the case, restate the problem and re-post.