NCERT Solutions for Class 10 Maths Chapter 9

Important NCERT Questions

SOME APPLICAT IONS OF TRIGONOMETRY

(Height and Distance)

NCERT Books for Session 2022-2023

CBSE Board and UP Board Others state Board

EXERCISE 9.1

Page No:204

Questions No:12

# From the top of a 7 m high building, the angle of elevation of the top of a cable tower is 60° and the angle of depression of its foot is 45°. Determine the height of the tower.

Share

Get here all the solutions of class 10 Maths Exercise 9.1

NCERT Solutions for class 10 Maths Exercise 9.1 all questions in Hindi Medium

Let AB is building and CD is cable tower.

In ΔABD,

AB/BD = tan 45° ⇒ 7/BD = 1 ⇒ BD = 7

In ΔACE, AC = BD = 7 m

CE/AE = tan 60° ⇒ CE/7 = √3 ⇒ CE = 7√3

Therefore, CD = CE + ED = 7√3 + 7 = 7(√3 + 1)

Hence, the height of the cable tower is 7(√3 + 1) m.