Answer:
9600 sq. yards.
Step-by-step explanation:
Carrie walked north 240 yards, turned and walked west 80 yards, and then turned and walked diagonally back to where she started.
Therefore, the path traced by Carrie is a right triangle with base and heights are 240 yards and 80 yards.
Now, the area of the triangle traced by Carrie while walking is
= 
=
sq. yards. (Answer)