The length of a rectangle is 2 more than its width. find the perimeter if its area is 15 ft^2

Area is length * width, so lw = 15
l = 2+w
so w(2+w) = 15 or w^2 +2w -15 = 0
Use quadratic formula to get (-2 +/- sqrt(4-4*1*-15))/2 or -5 and 3, but width cannot be negative, so 3 is the width. Plug into length, 3+2 = 5. Length is 5.
2*5 + 2*3 = 10+6 or 16 ft. 

You have 2 sides that are 2 cms and you have 6 sides that are 1/2 cm and you have 4 sides that are 1 cm. the smallest sides are 1/2 the medium sized sides are 1 and the smallest are 1/2. so to find the perimeter you have to add them all up together so your answer will be 11 cm's