Answer:
36 ft Â
Step-by-step explanation:
A = lw
Data:
A = 864 ft²
 l = length of basement
w = â…”l
Calculations:
864 = l × ⅔l
864 = ⅔l²
Multiply each side by 3:        2592 = 2l²
Divide each side by 2:          1296 = l²
Take the square root of each side: Â Â l = 36
The length of the basement is 36 ft.
Check:
w = â…”l = 24 ft
864 = 36 × 24
864 = 864