Last updated at June 23, 2017 by Teachoo

Transcript

Example 7 In Δ PQR, right-angled at Q (see Fig. ), PQ = 3 cm and PR = 6 cm. Determine ∠ QPR and ∠ PRQ. Given data, PQ = 3 cm PR = 6 cm Now, sin R = (𝑠𝑖𝑑𝑒 𝑜𝑝𝑝𝑜𝑠𝑖𝑡𝑒 𝑡𝑜 𝑎𝑛𝑔𝑙𝑒 𝑅)/𝐻𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠𝑒 sir R = 𝑃𝑄/𝑃𝑅 sir R = 3/6 sin R = 1/2 sin R = sin 30° R = 30° So, ∠ PRQ = 30° We know that, ∠ P + ∠ Q + ∠ R = 180° ∠ P + 90° + 30° = 180° ∠ P + 120° = 180° ∠ P = 180° - 120° ∠ P = 60° So, ∠ QPR = 60° Hence , ∠ PRQ = 30° ∠ QPR = 60°

Chapter 8 Class 10 Introduction to Trignometry

Example 2
Important

Example 6 Important

Example 7 Important You are here

Example 11 Important

Example 15 Important

Ex 8.1, 5 Important

Ex 8.1, 10 Important

Ex 8.1, 9 Important

Ex 8.3, 5 Important

Ex 8.1, 11 Important

Ex 8.3, 6 Important

Ex 8.3, 7 Important

Ex 8.4, 1 Important

Ex 8.4, 2 Important

Ex 8.4, 5 Important

Class 10

Important Questions for Exam - Class 10

- Chapter 1 Class 10 Real Numbers
- Chapter 2 Class 10 Polynomials
- Chapter 3 Class 10 Pair of Linear Equations in Two Variables
- Chapter 4 Class 10 Quadratic Equations
- Chapter 5 Class 10 Arithmetic Progressions
- Chapter 6 Class 10 Triangles
- Chapter 7 Class 10 Coordinate Geometry
- Chapter 8 Class 10 Introduction to Trignometry
- Chapter 9 Class 10 Some Applications of Trignometry
- Chapter 10 Class 10 Circles
- Chapter 11 Class 10 Constructions
- Chapter 12 Class 10 Areas related to Circles
- Chapter 13 Class 10 Surface Areas and Volumes
- Chapter 14 Class 10 Statistics
- Chapter 15 Class 10 Probability

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.