NECO 2024 · Paper 1 · Q48

Calculate the value of $y$ in the diagram, leaving your answer in surd form.

Worked solution (try it first)

The 6 cm side is the hypotenuse, and $y$ is the side next to the $30^\circ$ angle, so use cosine: $\cos30^\circ = \dfrac{y}{6}$ .
So $y = 6\cos30^\circ$
$= 6 \times \frac{\sqrt3}{2}$
$= 3\sqrt3$ cm, option A.