this is best solved using algebra
let the width be 4x (since it is 4 times more the length)
let the length be x
the formula for perimeter is (l+b)2 let us sub these variables in our formula
(x + 4x)2 = 64
expand brackets
2x + 8x = 64
combine like terms
10x = 64
make x the subject
x = 64/10 = 6.4
the length is 6.4 m
now let's find the width, the width is 4 times more the length so we simply substitute our value we found for x in 4x
we get:
4(6.4) = 25.6
the length is 25.6m
let's check our answers to see if its correct
25.6 + 6.4 = 32
32 × 2 = 64
the answer is correct