One application of the trigonometric ratios is to find lengths that you cannot measure. Very frequently, angles of depression and elevation are used in these types of problems.
Angle of Depression: The angle measured down from the horizon or a horizontal line.
Angle of Elevation: The angle measured up from the horizon or a horizontal line.
What if you placed a ladder 10 feet from a haymow whose floor is 20 feet from the ground? How tall would the ladder need to be to reach the haymow's floor if it forms a 30∘ angle with the ground?
