posted by ray .
The drawing shows a person looking at a building on top of which an antenna is mounted. The horizontal distance between the person's eyes and the building is 85.0 m. In part a the person is looking at the base of the antenna, and his line of sight makes an angle of 35.0 with the horizontal. In part b the person is looking at the top of the antenna, and his line of sight makes an angle of 38.0 with the horizontal. How tall is the antenna?
85 (tan 38 - tan 35) meters
This is more of a trigonometry than a physics question.
the question is a bit ambiguous in not specifying whether line of sight is UP from the horizontal or DOWN. the correct answer could be:
h = 85m[tan 38deg + tan 35deg]
...if the observer is in a window of a nearby building or on a hilltop, etc.
[many professors are ambiguous because they know the answer THEY want.]