Answer length=12ft and width=8 feet
Explanation-
P=2W+2L=2/W+L) = 40
2 (W+ L) = 40 Divide both sides by 2
W+L= 20
W=2+L/2
W+L= 20
2+1/2+1= 20
2+1/2+2112= 20
2 + 3 L/ 2 = 20 Subtract 2 to both sides
2+3112-2=20 -2
3 L/ 2 = 18 Multiply both sides by 3
3 L= 36 Divide both sides by 3
P=2L+2W formula for perimeter of a rectangle
40=2x+2[(x/2)+2]....substitute for "P, L, W"
=2x+x+4..............distribute 2 to each term in brackets
3x=36......................subtract 4 from each side, rewrite
∴ x=12.....................divide both sides by 3
∴ L=12 feet .............length is 12 feet
W=(12/2+2)
=6+2
∴ W=8 feet..............width is 8 feet