33a.
64/4 =16ppl on each side(this is a square, but a square is still a rectangle)
30/2+34/2= 15 by 17 ppl rectangle
28/2+36/2= 14 by 18 ppl rectangle
26/2+38/2= 13 by 19 ppl rectangle
24/2+40/2= 12 by 20 ppl rectangle
22/2+42/2= 11 by 21 ppl rectangle
20/2+44/2= 10 by 22 ppl rectangle
18/2+46/2= 9 by 23ppl rectangle
16/2+ 48/2 = 8 by 24 ppl rectangle
14/2+ 50/2 = 7 by 25 ppl rectangle
12/2+ 52/2 = 6 by 26 ppl rectangle
10/2 + 54/2 = 5 by 27 ppl rectangle
8/2+ 56/2 = 4 by 28 ppl rectangle
6/2+ 58/2 = 3 by 29 ppl rectangle
4/2+60/2 = 2 by 30 ppl rectangle
33b. The most appealing arrangement to me is the 16X16 square rectangle because all the sides are even.
Hope this helped!