13. Because it can't be divided by a whole number except 1 and itself. 14 can be Divided by 2. 21 and 33 can be divided by 3 making them composite or divisible by more than just 1 and itself :)
The length of the paintball machine could vary. If it is a square; then it would be 44.25 in. If it was a rectangle the answer Could be many different lengths, but one is 65 in (Width 23.5 in) I hope this helped ^^