URGENT PLEASE HELP BEEN ON THIS FOR HOURS As shown below, an observer (O) is located 900 feet from a building (B). The observer notices a helicopter (H) flying at a 49° angle of elevation from his line of sight. What is the height of the helicopter? Round to the nearest whole number and only enter in the numerical value, no units. (10 points)

Someone said you'll get the answer when you divide Tan(49°)/900
Does anyone know what that is??