# RD SHARMA Solutions for Class 10 Mathematics Chapter 12: Some Applications of Trigonometry

Trigonometry is one of the most ancient subjects studied by scholars. This is because of its vast application in the measurement of angles and lengths incorporated in building structures. It is also used for measuring distances and for navigation and transportation. In Chapter 6- Trigonometric identities, students learnt about the various functions and identities related to trigonometry. Chapter 12- Some Applications of Trigonometry utilises these concepts and teaches students how to implement them in daily life.

This chapter involves various real-life problems and elaborates the methods to implement trigonometric concepts to solve them.

Chapter 12-Some Applications of Trigonometry explains how to calculate the height of a structure. If an observer looks at the top of a structure, then the imaginary line from his position to the structure's apex is called the line of sight. The angle between the ground and the line of sight is called the angle of elevation.

Similarly, if the observer is standing at a specific height and can look at the top as well as the bottom of the building, then there will be two lines of sight the angle between the line of sight and the mid-span of the structure is called the angle of elevation whereas the angle between the mid-span of the structure and the line of sight looking at the bottom of the structure is called the angle of depression. The imaginary line between the observer and the mid-span can be referred to as the horizontal level.