what is the distance between two buildings, the shorter one is 200 meters with a depression of 20degrees and the longer one's height is unknown with an elevation of 10degrees
Please use the proper mathematical terms. We use "angle of depression" and "angle of elevation".
"Depression" is for psychologists.
We also need the position/location of the observer. Is the observer at a point between the buildings, or is the observer on the same side of both buildings, or is the observer at the same distance from both buildings?