Trigonometry, SMB-066

Find the value of \(\theta\), correct to the nearest degree. (2 marks)

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\(\theta=35^{\circ}\)

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\(\cos A\)	\(= \dfrac{b^2+c^2-a^2}{2bc} \)
\(\cos \theta\)	\(= \dfrac{16.2^2+18.1^2-10.5^2}{2 \times 16.2 \times 18.1}\)
	\(= 0.818…\)
\(\therefore \theta\)	\(= \cos^{-1} (0.818…) \)
	\(=35.09…^{\circ} \)
	\(=35^{\circ}\ \ \text{(nearest degree)} \)