Answer:
2122.64 ft^2
Explanation:
The sprinkler turns by 90 degree, it means it covers the one fourth part of a circular area.
Area covered = [tex]\frac{\pi r^{2}}{4}[/tex]
Where, r be the radius of the circular part.
r = 52 feet
Area = [tex]\frac{3.14\times 52^{2}}{4}[/tex]
Area = 2122.64 ft^2