This expression is a difference of squares:

Answer:
The answer is A.
Step-by-step explanation:
I pirnt the picture out and grabbed a ruler and started looking for the answer and If you look at A. with a ruler you can tell that it is a 45° angle.
2 cm = 8 feet.
4 / 2 = 2. 8 * 2 = 16. 16 feet in width.
Now, the length:
6 / 2 = 3. 8 * 3 = 24. 24 feet in length.
The actual dimensions are 16 feet in width and 24 feet in length.
8 21/100 is the mixed number for8.21