Mathematics 4024 · O Level · Non-right-angled triangles

Non-right-angled triangles — practice question

The diagram depicts a triangular field $ABC$. The lengths are $AB = 95\text{ m}$, $BC = 132\text{ m}$ and $AC = 174\text{ m}$.
(a)[3]

Show that $\angle BAC = 48.6^\circ$, accurate to $1$ decimal place.

(b)[4]

Flower seeds are used to sow the field. For every square metre, $3$ grams of seed are needed. The seed is priced at $\$8.50$ for $100$ grams. Calculate the cost of the flower seed needed for the field.

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