Answer:
x = 664.093 m
Explanation:
tan∅ = opposite over adjacent
Since we are trying to find the horizontal distance, that means we are dealing with the bottom length and not the hypotenuse (the diagonal length):
Our theta (∅) = 52°
Our opposite = 850 m
Our adjacent = x m
tan52° = 850/x
xtan52° = 850
x = 850/tan52°
x = 664.093 m