## Maths Class 10 Notes for 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.