You have that the man is 25 feet up and the distance between the person on the street and the man in the building is 50 feet. Therefore, you mus aplpy the proccedure below to solve this exercise:
Tan^-1(α)=Opposite/Adjacent
α is the angle of elevation.
Opposite=25 feet
Adjacent=50 feet
When you substitute these values into Tan^-1(α)=Opposite/Adjacent, you obtain:
Tan^-1(α)=Opposite/Adjacent
Tan^-1(α)=25/50
α=26.56°
Therefore, the answer is: 26.56°
