A pedestrian is an between two tall building, from a point 10 meter high on the first building, the angle of depression of the pedestrian is 20°,10' from the same point, the angle of elevation of the top of the second building is 15°,20'. If the two building are 40 meter apart. How far is the pedestrian from second building?

Answer 1

If the pedestrian is x meters from the short building,

10/x = tan20°10'

the distance to the tall building is 40-x

You don't seem to care how tall the other building is, but if the tall building has height h, then

(h-10)/40 = tan15°20'