Let the height of the building be h m and the distance between the building and tower be d m.
The tower height is 50 m.
From the foot of the tower, the angle of elevation to the top of the building is 30°.
tan(30°)=dh
31=dh
d=h3 ... (1)
From the foot of the building, the angle of elevation to the top of the tower is 60°.
tan(60°)=d50
3=d50
d=350 ... (2)
The distance d is the same in both cases. Equating (1) and (2):
h3=350
h×3×3=50
h×3=50
h=350
Therefore, the height of the building is 350 m.