Explanation:
Let width be x
according to question
length = 2x-4
perimeter = 58
now,
perimeter = 2(length + width)
58 = 2(x+2x-4)
58 = 6x-8
6x = 66
x = 11
putting value of x in length
2x-4
= 2 X 11 -5
= 18
hence the dimensions of the rectangle is 18 and 11