Mathematics Class X Notes – Some Applications of Trigonometry

LINE OF SIGHT

Suppose we are viewing an object standing on the ground. Clearly, the line of sight ( or line of vision) to the object is the line from our eyes to the object, we are viewing.

(A) Angle of elevation :

Let `0′ be the eye of observer and Q be an object and OX is a horizontal line then ∠XOQ is called the angle of elevation and generally it is denoted by
Theeta or Phie i.e ‘0’ or φ.

(b) Angle of Depression: ‘P’ be the object lies below the horizontal

line OX, then ∠XOP is called the angle of depression and is denoted by ‘0’ or `φ’

NOTE: For solving the height and distances problem, draw figure, and see the relation between known to unknown.