Answer: The length is 6 feet and the width is 10 feet.
Step-by-step explanation: The question has specified the area as 60 (square feet) and the length and width are yet unknown. However we know that the length is 4 feet less than the width. What this means is that, if the width is W, then the length is W - 4.
We can now write an equation for the area of the rectangle as follows;
Area = L x W
60 = (W - 4) x W
60 = W^2 - 4W
If we rearrange all terms on one side of the equation, we now have
W^2 - 4W - 60 = 0
This is a quadratic equation and by factorizing, we now have
(W + 6) (W - 10) = 0
Hence,
Either W + 6 = 0 and then W = -6
Or W - 10 = 0 and then W = 10
We know that the side of the rectangle cannot be a negative value, so we go with W = 10.
Having calculated W as 10, the length now becomes
L = W - 4
L = 10 - 4
L = 6
Therefore, length = 6 feet and width = 10 feet
