For each piece we have that the area is:
A = (b) * (h)
Where,
b: base of the parallelogram
h: height of the parallelogram
Substituting values:
A = (4) * (2.5)
A = 10 in ^ 2
Then, for 85 pieces we have:
(85) * (10) = 850 in ^ 2
Answer:
the total area of the border was:
850 in ^ 2