[填空题]
The following diagram smyg p 5,p28nm*6bzqqe*-xug teh j q;hsa xvgyi;p puhxi80+.68f)(shows a right-angled triangle ABC and a sector CBE of a circle with centre C. The point D lies on [AC] such that [BD] is perpendicular to [AC]. The region R is bounded by [BD], [DE]h-e x8vpxi)ehsq ;j. 86h*a (ugtg;yp+fxi 0 u and arc BFE.
Find the area of the shaded region R.≈ $cm ^2$[/BD][/BD]
