The diagram shows a circle centre \(O\), radius \(10\) cm. The points \(A\), \(B\) and \(C\) lie on the circumference of the circle such that \(AB=BC=18\) cm.

(i) Show that angle \(AOB=2.24\) radians correct to 2 decimal places.

(ii) Find the perimeter of the shaded region.

(iii) Find the area of the shaded region.