JAMB 2010 · UTME · Q30

From the cyclic quadrilateral $TUVW$ , where $\angle TUV = (3x + 20)^\circ$ and $\angle TWV = 88^\circ$ , find the value of $x$ .

Worked solution (try it first)

$\angle TUV$ and $\angle TWV$ are opposite angles of the cyclic quadrilateral, so they add up to $180^\circ$ : $3x + 20 + 88 = 180$ .
Simplify: $3x + 108 = 180$ , so $3x = 72$ .
Divide both sides by 3: $x = 24$ , option C.