Two office buildings are 51 meters apart

Two office buildings are 51 m apart. The height of the taller building is 207 m. The angle of depression from the top of the taller building to the top of the shorter building is 15∘.

Find the height of the shorter building to the nearest meter. How can a diagram help you? How does the angle of depression from the top of the taller building relate to the angle of elevation from the top of the shorter building?