Here are the solutions for question 3. Question 3: The vertices of the quadrilaterals below lie on the circumference of the circle. Determine the value of the unknown variables. We need to find the values of $x, y, z,$ and $w$. Step 1: Find $x$. The angle $x$ is $\angle BCS$. Consider the cyclic quadrilateral ABRS. The sum of opposite angles in a cyclic quadrilateral is $180^\circ$. We are given $\angle BAS = 60^\circ$. Therefore, $\angle BRS + \angle BAS = 180^\circ$. $$\angle BRS + 60^\circ = 180^\circ$$ $$\angle BRS