angle of elevation

Question

from a 75ft observation tower a controller sights a hot air ballon at an angle of elevation of 20 degree. if horizontal distance from the tower is 300 feet . what is the elevation of the ballon?

Answer 1

It will be easier to visualize once you draw a figure. 

If h is the elevation  of the baloon, then,  (h-75)/(300)= Tan 20⁰

Therefore, h-75= 300 tan 20⁰

So,  h= 75 + 300 x tan20⁰