A CCTV camera is mounted on a wall that is 9.5 feet above a security desk in an office. It is used to view an entrance door 11.5 feet from the desk. Find the angle of depression from the camera lens to the entrance door.
Sol:
Height of CCTV camera = 9.5 feet
Distance of entrance door from the security desk = 11.5 feet
To find the angle of depression ∠CAD, we must find the angle ∠ACB.
Since these angles are alternate angles and are equal.
∴ In triangle ABC,
∴ The angle of depression is 39.55°.