Three planes a distinct lines have in common
The total area of the stable is 20,250 sq. ft.
Let n = total number of box stalls.
Each box stall is a square of length 9 ft.
Total area = 9^2n = 81n ft².
Therefore
81n = 20250
n = 20250/81 = 250
Answer: 250 horses.
The correct answer is 34.0 ft.
