a window in one building, the angle of elevation to the top of a second, taller building is 38°. The angle of depression to the base of the taller building is 51°. Determine the height of the second, taller building to the nearest metre if the two buildings are 42m apart.

Answer 1

A sketch really really helps.
On mine I drew a horizontal from the window to the taller building and
got 2 right-angled triangles
from there:
tan 51 = (height from base to window)/42
tan 38° = (height above window)/42

solve for "height from base to window" and (height above window)
then add them up