Answer:
52.1m
Step-by-step explanation:
Please see attachment for explanatory diagram.
From the diagram:
Opposite = H
Adjacent = 20m
Angle θ = 69°
The height, H of the building can be obtained as follow:
Tan θ = Opp /Adj
Tan 69 = H/20
Cross multiply
H = 20 x Tan 69
H = 52.1m
Therefore, the height of the building is 52.1m