algebra
posted by ella .
Mike would like to plant some trees so he needs to use a portion of his existing yard. The perimeter of this rectangular portion needs to be 14 yards and the diagonal is 5 yards. Can you help Mike determine the length and width of this new portion? Mike requested that you show him how you arrive at the answers, so please show your complete work.

An old Greek did this already.
5^2=w^2+L^2 I hope you recognize that formula...
but 2w+2L=14 or w=7L
25=(7L)^2 + L^2
solve for L and you have it.