Luke wants to fence a square piece of land of at least 400 square feet. What should the side of the square be if he wants to use the least amount of fencing?
To minimize the amount of fencing, Luke should make the square as small as possible, while still having an area of at least 400 square feet. The area of a square is the square of its side, so I can write an equation: s^2 = 400, where s is the side of the square. To solve for s, I can take the square root of both sides: s = sqrt(400). The square root of 400 is 20, so the side of the square should be 20 feet. 