WAEC 2019 · Paper 1 · Q40

In the same diagram ( $RT$ a tangent at $R$ , $\angle PQR = 70^\circ$ , $\angle QRT = 52^\circ$ ), find the value of $x = \angle PRQ$ .

Worked solution (try it first)

Alternate segment: $\angle QPR$ also stands on chord $QR$ , so $\angle QPR = \angle QRT = 52^\circ$ .
The angles of triangle $PQR$ add up to $180^\circ$ : $x = 180^\circ - 70^\circ - 52^\circ$
$= 58^\circ$ , option B.