First let's find the perimeter of the scale drawing. The perimeter is the sum of all sides of the figure.
Looking at the figure, there are two sides without the length. The length of the vertical missing side can be calculated as 8 - 2 = 6 cm, and the length of the horizontal missing side can be calculated as 20 - 9 = 11 cm.
So the perimeter of the scale drawing is:
Now, to find the perimeter of the garden, we can use a rule of three:
So the perimeter of the garden is 280 ft.