Question 946919
Hint:


Your sketch will look something like this.
<img src = "http://i150.photobucket.com/albums/s91/jim_thompson5910/4o2rd951riupu978ddb3-1_zps37f7d023.png">
I have the camera placed at the top left corner of building B. The horizontal distance between the two buildings (edge to edge) is unknown. We'll call it d for now.


Focus on building A. Specifically the vertical height of this building. We know that building B has a height of 120 meters. The first 120 meters, starting from the ground, is accounted for and shown in the drawing because of building B's height. This is assuming both buildings are on the same level flat ground at the same height above sea level. The rest of the height is unknown. We'll call this h. Therefore, building A has a total height of {{{120+h}}} meters.


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here's how you'll go about solving


first you'll find the value of d. We have a right triangle (the red dashed triangle), so we can use trig ratios.


tan(angle) = opposite/adjacent
tan(36) = 120/d


solve for d to get an approximate decimal number. This will be the approximate distance between the two buildings.


Once you know the value of d, you can use it to find h


tan(angle) = opposite/adjacent
tan(47) = h/d


you plug in the approx value of d found beforehand, then solve for h. The total height will be {{{120+h}}}