Let's begin by dividing the figure into shapes we can more easily calculate the area of:
We have divided the figure into rectangles 1, 2 and 3. Le'ts first observe that the base of rectangle 2 will measure 3m, since 22-7-12=3. Likewise, its height will measure 7m since 9-2=7.
From here, we can calculate the area of each rectangle using the formula
where b is the lenght of the base and h is the lenght of the height. Using this formua on each rectangle we get:
Knowing this, the area of the whole figure will be
Finally, we sum the digits of this area:
So the answer is 12m.