A high school student measured the elevation of the top of the building to be 40 degrees. Moving 20 meters closer to the building, he found the elevation to be 60 degrees. What is the approximate height of the building?
Tan 40 = opp/adj = h / (20+x)
Tan 60 = opp/adj = h / x now you have two equations and two unkinowns
Do you think you can solve this system of equations for 'h' ?