Question

you want to make a rectangular dog pen using 20 yards od fencing. The side lengths must be in whole yards. create as many different rectangular pens as you can

Answer 1

rectangular with whole numbers
perimiter=legnth+legnth+width+width=2l+2w
therefor
p=2l+2w=2(l+w)
p/2=l+w

perimiter=20
20=2l+2w
divide by 2 to make simpler
10=l+w
find all combos
l>w so
l=9 and w=1
l=8 and w=2
l=7 and w=3
l=6 and w=4

combos