Question 65046
Let L be the length and W be the width.
We know that the house is 6 feet longer that it is wide, which translates into the length being 6 times bigger than width. Therefore:
L = 6W. 
Perimeter P = 2L+2W=2*6W + 2W = 14W=56, thus W=4 and therefore L = 24. 
Check: 2*24 + 2*4 = 56

Hope it helps,
Cristiana