The angle of elevation of an object as seen by an observer is the angle between the horizontal and the line from the object to the observer's eye (the line of sight). If the object is below the level of the observer, then the angle between the horizontal and the observer's line of sight is called the angle of depression.
<span>The main ratio that we use to find the angle of depression is tangent. The angle of depression may be found by using this formula: tan y = opposite/adjacent. The opposite side in this case is usually the height of the observer or height in terms of location, for example, the height of a plane in the air.</span>
