Question 163393
L = length
W = width
assume the length will be against the house.  
length can be less than width if need be.
length can be same as width if need be (square).
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formula for Area of patio is length * width = L*W.
formula for perimeter of patio is L + 2W.
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this is because you do not want to include the length of the patio that is against the house in determining material required for the perimeter.
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if she calls the length "x", then the width can be anything in terms of x.
L = x
W = 2*x
W = x+c where c is a constant.
W = x-c where c is a constant.
W = x/2
any of these will work.
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in the area formula, you substitute x for L and substitute whatever the value you want for W in terms of x.
example:
L = x
W = 2*x+3
then A (area) = L*W = x*(2*x+3)
P = L + 2*W = x + 2*(2*x+3)
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just give x a value and everything else falls into place.
example:
let x = 15
L = x
W = 2*x+3
substituting 15 for x gets
L = 15
W = 33
A = L*W = 15*33
P = L + 2*W = 15 + 2*33
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