Physics
posted by Jo Rellama .
a television antenna is on the roof of the building. from a pt. on the ground 36.0 feet from the building , the angle of elevation of the top and the bottom of the antenna are 51 degree celsiusand 42 degree celsuis respectively. how tall is antenna?

The height of any object viewed from a horizontal distance d and angle of elevation θ is d*tan(θ).
Let's say the top of the roof viewed from the ground 50 ft away is 30°.
The height of the roof is therefore
H=50tan(30°)=28.9 feet.
Use the same formula to get the height from the ground of the top and bottom of the antenna. The height of the antenna is therefore the difference between the two heights from the ground. 
The antenna is 12.05 ft tall.