Question 1091499
If this is drawn, alternate interior angles allow the same problem to be the angle of elevation to the balloon from each building.  
from the closer building, tan 82=3km/distance to point below balloon.
distance=3/tan 82=0.42 km.
For the further building, distance=3/tan 12=14.11 km to point below balloon.
The two buildings are 13.69 km apart