(a(i))[2]
Determine the size of one interior angle of a regular $15$-sided polygon.
(a(ii))[2]
The diagram displays part of a regular $15$-sided polygon. Determine the value of $x$.
(b)[4]
$A$, $B$, $C$ and $D$ are points on the circle, centre $O$. $AB$ is a diameter of the circle. Angle $BAC = 24^{\circ}$. Determine angle $ADC$. Give a reason for each step in your working.