A group of architects is designing a large, circular park boundary. They plan to place four decorative stone pillars at points \(A\), \(B\), \(C\), and \(D\) on the circular boundary to form a quadrilateral \(ABCD\). This quadrilateral must be a cyclic quadrilateral. The architects have already fixed the positions for three pillars such as: The measure of angle \(\angle DAB\) is \(111^{\circ}\) and \(\angle ABC\) is \(84^\circ\). The pillar at \(C\) is placed such that side \(BC\) is produced to a point \(E\) outside the circle.
(i) The measure of the angle \(\angle BCD\) __________\(^\circ\).
(ii) The measure of the angle \(\angle ADC\) __________\(^\circ\).
(iii) The measure of exterior angle \(\angle DCE\) _________\(^\circ\).
(iv) A quadrilateral is cyclic if