Okay so I have looked at this and I think I know how to do it...
since its an irregular shape you need to section it into shapes, so for this you have a square and a rectangle.
So lets start with triangle... (base × height)/2
It looks like the base of the triangle is the side that says 12 for the whole shape.
Subtract 5 from 12 you get 7 so the base is 7
The Height is 5
So your equation is...
(7 x 7)/2
(49)/7
7
Next is the square... a^2
5 x 5
25
Add them together...
7 + 26 = 32
And you get your area of 32
Hope this helps!