If the width is 2 cm less than its length, the expression is this: w = L - 2. The length then is just L. The perimeter formula is 2L + 2w = P. Filling in accordingly, we have 2L + 2(L-2)=52 and 2L + 2L - 4 = 52. 4L = 56 and L=14. The width then is 12. There you go!
