Area of shaded region (2 triangles)

Question

Find the area of the shaded region.

I don't really have any idea how to do this. Is it possible to find the area or there is a lack of information to answer this question?

Answer 1

Area of ABF = 1/2 x 5 x 4 = 10

Area of DBF = 1/2 x 10 x 4 = 20

Area of CBF = 1/2 x 4 x 3 = 6

Area of shaded region = 10 + 20 - 2 x 6 = 18