So it's tricky since it says use a function, but all a function is is a "machine" where you put in something a get an output. In this case, the sides of the yard are all x, which means I can say x is 1, or 2, or 3, etc. All you have to do to make the function is show what the perimeter would be for each of those inputs. So as I very poorly showed in the picture, the perimeter would be 12x, so whatever the input is, you plug that x value in and you find your perimeter. So your function is P= 12x
