Step-by-step explanation:
Length = 6x
width = let x be width
Perimeter = 84 in
Now
Perimeter = 2 ( l + b )
84 = 2 ( 6x + x )
84 = 2 × 7x
84 / 2 = 7x
42 = 7x
x = 42 / 7
x = 6
now
width = 6 yards
length = 6x = 6 × 6 = 36 yards
now
area = l × b
= 6 × 36 yd
= 216 yd²
