Question 1155235
*[illustration stack.png].
Here  dimensions are 3 ft. Wide, and 7 ft. Long and height of stack = 0.69 ft

Surface area of one stack = 2*(LW+WH+LH)

= 2*(7*3  +3*0.69+7*0.69)
= 55.8 ft^2

Multiply by 2 to to get surface area of 2 stacks separately