Using the given ratio, we let 6x be the length and x be the width. The perimeter of a rectangle is given by:
P=2l+2w
Substituting given, we have:
56=2(6x)+2(x)
Solve for x:
56=12x+2x
56=14x
5614=x
4=x
So, the length is 6(4)=24 inches and the width is 4 inches4 inches.