NECO 2024 · Paper 1 · Q41

Find the value of $y$ in the diagram.

Worked solution (try it first)

Angles on a straight line: the interior angle at the top vertex is $180^\circ - 123^\circ = 57^\circ$ .
$y$ is an exterior angle of the triangle, so it equals the sum of the two opposite interior angles: $y = 75^\circ + 57^\circ = 132^\circ$ , option D.