The problem says that Brandon sights a helicopter above a building that is 200 feet away at an angle of elevation of 30 degrees. So, you can calculate the height asked, by following this procedure:
Tan(α)=Opposite leg/Adjacent leg
α=30°
Opposite leg=x
Adjacent leg=200 feet
When you substitute these values into the formula above (Tan(α)=Opposite leg/Adjacent leg), you have:
Tan(α)=Opposite leg/Adjacent leg
Tan(30°)=x/200
You must clear "x":
x=200xTan(30°)
Therefore, the value of "x" is:
x=115 feet
How high above the ground the is the helicopter?
The answer is: 115 feet
