There are 5280 feet in a mile.
Area is base x height
4x2=8 cm
I think your answer might be 19.5
Answer:
Approximately 17.88x or 
Step-by-step explanation:
Use pythagorean formula. In a rhombus the diagonals bisect each other and they are perpendicular, so you could have a right triangle with legs of 2x and 4x, the hypoteneuse would then be
which is approximately 4.47x. In a rhombus all 4 sides are the same, so multiply that by 4 and you get the perimeter. 4(4.47x) = 17.88x or if you simplify the radical instead it's 
Rectangular with whole numbers
perimiter=legnth+legnth+width+width=2l+2w
therefor
p=2l+2w=2(l+w)
p/2=l+w
perimiter=20
20=2l+2w
divide by 2 to make simpler
10=l+w
find all combos
l>w so
l=9 and w=1
l=8 and w=2
l=7 and w=3
l=6 and w=4
combos