Answer:
The least amount of fabric are 22 square feet
Step-by-step explanation:
we know that
The surface area of a rectangular prism is given by the formula

where
B is the area of the base
P is the perimeter of the base
H is the height of the prism
Let
L ---> the length pf the prism
W ---> the width of the prism
H ---> is the height of the prism
Let

Find the area of the base

Find the perimeter of the base

Find the surface area

therefore
The least amount of fabric are 22 square feet
The area of the square is increasing at the rate of 36(3/2)^(1/2).btw,i forget to add ^2 to `cm`
So it would be in six years because if you do it, it would be
garden 1: 2,4,6,8
garden 2: 3,6,9
and the lowest common multiple is 6 so in 6 years is when it will happen again