Answer:
400 ft²
Step-by-step explanation:
The maximum area of a rectangle results from it being a square. The rectangle (or square) must have 4 equal sides in order to maximize area. But in this case, one side is a wall. That means that the remaining three sides will be = 60 / 3 = 20 feet long. You formed an square that is 20 ft x 20 ft = 400 ft²
length = 1/2 w+9
perimeter= 60 =2(l+w)
substitute in for length
60 = 2(1/2 w +9 +w)
60 = 2 (3/2 w +9)
distribute
60 = 3w + 18
subtract 18 from each side
42 = 3w
divide by 3 on each side
14 = w
length = 1/2 w + 9
length = 1/2 (14) +9
7 + 9
16cm
Here is a photo of the decimal places
