Question 924960
The perimeter of the rectangle is 34 feet. The width is 5. 
There are two widths and two lengths in a rectangle. 
This is how we create our formula to find the length, or longest side:

(w=width L=length)

34=2w x 2L

34=2(5) x 2L

34=10 x 2L

24=2L

12=L

The length, and longest side, of the rectangle is 12 feet. 

ratio of longest side to the perimeter

12:34

simplified: 6:17<<<<<<<<<<<Your answer!

Good luck with your homework!
Cheers, 
Sami