Explain where to place the two beams 16.58

Acollege is planning to construct a rectangular parking lot on land bordered on one side by a highway. the plan is to use 680 feet of fencing to fence off the other three sides. what dimensions should the lot have if the enclosed area is to be a maximum?

This is about circle theorems. someone asap : (

Which fraction represents the ratio 35 : 42 in simplest form