perimiter is 20ft
width is
what
do you mean the width is 8 feet less than the length? or 4ft less?
anyway
P=2(L+W)
20=2(L+W)
divide by 2
10=L+W
and
L=10-W
width is 4ft less than length (I assuming)
W=-4+L
repalce W with -4+L
L=10-(-4+L)
L=10+4-L
L=14-L
2L=14
L=7
W=-4+L
W=-4+7
W=3
it is 7ft by 3ft