With this, it matters about what isn't there.
It looks like this shape would be a perfect square, with rectangles cut out of it.
So, 12*7=84
Now, cut rectangles out of it.
There are two rectangles with the same dimensions.
6*5=30
There are two of them, so 30*2=60
Now, subtract.
84-60=24
Area is 24 square inches