[填空题]
The following diagram shows a right-angled triane9e,o n/tp ivj9q l*c7p-rhr+gle ABC8f:nufzzam br: d*u 3/dk 2(fu and a sector CBE of a circle with centre C. The point D lies on [AC] such that [BD] is perpendicular to [Afaznbz8kuu/:f *( fum32 drd:C]. The region R is bounded by [BD], [DE] and arc BFE.
Find the area of the shaded region R.≈ $cm ^2$[/BD][/BD]
