L = length = unknown
W = width = 0.1 meters
A = area = 7.1 square meters
Use the formula for an area of a rectangle. Isolate L
A = L*W
7.1 = L*0.1
0.1*L = 7.1
L = 7.1/0.1
L = 71
The rectangle has a length of 71 meters and a width of 0.1 meters (which multiply to an area of 7.1 square meters)
Now use the perimeter formula
P = 2*(L+W)
P = 2*(71+0.1)
P = 2*71.1
P = 142.2
Or you can add up the four sides 71, 71, 0.1, 0.1 and you'll get the same answer.
Final Answer: 142.2 meters
