A geometry and an algebra problem

[Jongy]

These problems are from the Seton Hall Competition:
1) Quadrilateral ABCD of perimeter 684 inches is inscribed in a circle; the lengths of sides AB, BC, CD, and DA form an arithmetic sequence with AB<BC<CD<DA. If the secant of angle BAD has value 89, find the largest side of quadrilateral ABCD.

2)Let A and N be integers. Bob earns 2A dollars the first week, A/4 more than that the second week, and so forth, each successive week earning A/4 more than the previous week. Ron earns A dollars the first week, A/2 more than that the second week, and so forth, each successive week earning A/2 more than the previous week. After both have worked for N weeks, Ron has earned $252 more than Bob. The sum of Bob's earnings in the third week and Ron's earnings in the second from last wek was$100. How much did Bob earn in N weeks?