help me with this ASAP please show short solution no need to explain or anything solve ASAP

7. A television camera is positioned 8 km from a helicopter landing pad. The helicopter is rising vertically with a speed of 2 km/h. If the television camera is always kept aimed directly at the helicopter, how fast should the camera's angle of elevation be changing when the helicopter is at 3 km altitude? (The angle of elevation is the angle between the ground and the camera's line of sight.)