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Example 7 - In PQR, PQ = 3 cm, PR = 6. Find QPR and PRQ - Examples

Example 7 - Chapter 8 Class 10 Introduction to Trignometry - Part 2

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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°

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.