Bunuel

In the figure, ABCD is a rectangle, and BE and CF are arcs of circles centred at A and D. What is the area of the shaded region?
A. \(10 - \pi\)
B. \(2(5 - \pi)\)
C. \(2(5 -2\pi)\)
D. \(6 + 2\pi\)
E. \(5(2 - \pi)\)
Attachment:
2018-07-20_1100.png
we are asked to find out the area of the shaded portion. This can be done as follows :
Area of the shaded portion : Area of the rectangular - Area of the sector of the 2 circles. Area of the rectangular : 5*2 = 10
Area of the sector of the circle: pie*\((r)^2\) * C/360. Where c is the central angle. As sector is the part of rectangular , central angle must be 90 degree.
= pie * (2)^2 * 90/360.............width of the rectangular has become the radius of the circle.
= pie
but this one is the area of a circle. we have 2 sectors.
So, total area of 2 sectors: 2 pie
Area of the shaded portion : 10 - 2 pie
= 2( 5 - pie )
The best answer is B.