For this case we have the following question:
"if the perimeter of a square is 80cm, find the area"
By definition, the perimeter of a square is given by:
[tex]P = 4l[/tex]
Where:
l: It is the side of the square
According to the data of the statement we have:
[tex]P = 80 \ cm[/tex]
So:
[tex]80 = 4l[/tex]
We clear the value of "l":
[tex]l = \frac {80} {4}\\l = 20[/tex]
By definition, the area of a square is given by:
[tex]A = l ^ 2\\A = 20 ^ 2 = 400 \ cm ^ 2[/tex]
Answer:
[tex]400 \ cm ^ 2[/tex]
