Fencing needed: 2*pi*18 = just over 113 meters
Fencing needed: 2pi19 = just over 119.4 meters
Length of fencing needed = 2*pi*10 = 20*pi feet
18 meters of fencing. You simply need to find the circumference of the rectangle.
pi x diameter = 3.14 x 10 = 31.4 feet
Depends on the shape of the area (see the answer to the same question relating to 2 acres). If the area was an infinitely thin strip, the length of fencing would be infinite. For a circular area, the least amount of fencing would be needed.
you need to find the dimensions of the backyard. if it's fencing, it's most likely going around 3 sides of your backyard (the 4th side is your house). so 2 times length, then add width.
A length of approx 18.85 feet.
Circumfence 2 x 15 x pi = 94 feet 3 inches