WAEC 2025 · Paper 1 · Q40✱✱

In the diagram, $AB \parallel CD$ . What is the size of the angle marked $x$ ?

Worked solution (try it first)

Vertically opposite angles: $AB$ also makes $52^\circ$ with the upper line on the other side of the crossing.
$CD \parallel AB$ , so $CD$ makes the same $52^\circ$ with the upper line (corresponding angles).
This angle is inside the small triangle cut off by $CD$ at the $35^\circ$ vertex.
The angles of that triangle add up to $180^\circ$ : $x = 180^\circ - 52^\circ - 35^\circ$
$= 93^\circ$ , option A.