WAEC 2025 · Paper 1 · Q43✱✱

In right-angled triangle $PQR$ , $\angle PRQ = 90^\circ$ , $\angle QPR = 30^\circ$ and $|PQ| = 10\text{ cm}$ . Find $|QR| = y$ .

Worked solution (try it first)

The right angle is at $R$ , so $PQ = 10$ cm is the hypotenuse, and $QR = y$ is opposite the $30^\circ$ angle at $P$ .
So $y = 10\sin30^\circ$
$= 10 \times \frac12$
$= 5$ cm, option C.