Answer: Length = 24; width =4
Explanation
 Since the ratio of the length to width is 6:1
 Let the length be represented as 6x 
And the width be = x
Such that that the Perimeter of the rectangle which is 
 Perimeter = 2(length + width) becomes 
56 = 2(6x + x)
 56/2 = 6x+x 
28 = 7x 
x = 4
Width = 4
 Length = 6x= 6 x 4 = 24