Find the area of the shaded region in the figure below: Find the area of the shaded region in the figure below:

I am completely stuck on how to start off this question. Please help on some guidance on how to start it off.


Split the square into $8$ triangles, convince yourself you can group them into 4 pairs
and each pair has same area. Let the area of the triangles be $a, b, c, d$ as illustrated above. 
You are given $c + d = 20$, $b + c = 32$ and $a + d = 16$. The area of the quadrilateral (in cyan) is
$$a + b = (a + d) + ( b + c) - ( c + d) = 16 + 32 -20 = 28$$
