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:9
The angle of elevation of the top of a building from the foot of the tower is 30° and the angle of elevation of the top of the tower from the foot of the building is 60°. If the tower is 50 m high, find the height of the building.
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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 CD is 50m high tower and AB is building.
In ΔCDB,
CD/BD = tan 60° ⇒ 50/BD = √3 ⇒ BD = 50/√3
In ΔABD,
AB/BD = tan 30° ⇒ AB/(50√3) = 1/√3 ⇒ AB = 50/√3 × 1/√3 = 50/ 3 = 16 (2/3)
Hence, the height of the building is 16(2/3)m.