Brandon sights a helicopter above a building that is 200 feet away at an angle of elevation of 30 degrees. to the nearest foot, how high above the ground the is the helicopter

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