ok so assuming you ahve a rectangle (since you gave legnth and width)
area=legnth times width
perimiter=L+L+W+W=2L+2W=2(L+W)
area=36
some factors are
6 and 6
4 and 9
3 and 12
2 and 18
1 and 36
those are only whole numbers, but tat is for ease
so add and mutliplyby 2 (preimiter
6 and 6, P=2(6+6)=24
4 and 9, P=2(4+9)=26
3 and 12, P=2(3+12)=30
2 and 18, P=2(2+18)=40
1 and 36, P=2(1+36=74