Example 7 - Chapter 8 Class 10 Introduction to Trignometry (Term 1)
Last updated at Dec. 24, 2019 by Teachoo
Examples
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Example 8 Important
Example 9 Deleted for CBSE Board 2022 Exams
Example 10 Important Deleted for CBSE Board 2022 Exams
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Example 12
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Chapter 8 Class 10 Introduction to Trignometry (Term 1)
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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°
