Let DF be x and FC be y and the height of the rectangle (BC) be h. Asshown in figure below:
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Inkedrectangle_LI.jpg [ 567 KiB | Viewed 5806 times ]
Now area AECF =2 and writing it in terms of our variable we get
area AECF =2= \(y \times h\).
Similarly area EBFD =3 and writing it in terms of our variable we get
area EBFD =3= \(x \times h\).
Now area of the rectangle is clearly =\((x+y) \times h\).
Clearly if we add the area of EBFD and AECF we get the area of rectangle = \((x+y) \times h= x \times h + y \times h = 3+2= 5\)
Hence option C