In triangle PQR, right-angled at Q (see Fig. ), PQ =3 ,cm and PR =6 ,cm . Determine ∠ QPR and ∠

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8. Introduction to Trigonometry

hard

In $\triangle$ $PQR,$ right-angled at $Q$ (see $Fig.$), $PQ =3 \,cm$ and $PR =6 \,cm$. Determine $\angle QPR$ and $\angle PRQ$.

Option A

Option B

Option C

Option D

Solution

Given $PQ =3\,cm$ and $PR =6 \,cm$

$\frac{ PQ }{ PR }=\sin R$

$\sin R =\frac{3}{6}=\frac{1}{2}$

$\angle PRQ =30^{\circ}$

$\angle QPR =60^{\circ}$

Standard 10

Mathematics

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