Answer:
344 ft²
Explanation:
The area of the square is (40 ft)² = 1600 ft².
The area of the four circles is ...
4×(πr²) = 4×3.14×(10 ft)² = 1256 ft²
Then the area that is not covered by the circles is ...
1600 ft² -1256 ft² = 344 ft²
The area not sprinkled is 344 ft².