In the diagram, OAB and OCD are radii of a circle, centre O and radius 16 cm. Angle AOC = \(\alpha\) radians. AC and BD are arcs of circles, centre O and radii 10 cm and 16 cm respectively.

(i) In the case where \(\alpha = 0.8\), find the area of the shaded region.

(ii) Find the value of \(\alpha\) for which the perimeter of the shaded region is 28.9 cm.