Suppose side of the square farm = x ft
area of farm = x^2 = 280
x= sqrt ( 280) = 16.733 feet
Perimeter of the square farm = 4 times the side length
= 4* 16.733
= 66.93 ft
If the length is doubled the new length = 2* 16.733 = 33.46
The new perimeter = 4 times the length of side = 4* 33.46 =133.86 feet
Answer : 66.93 and 133.86