We can split the shape into a square of lengths, 12*12 and a triangle of lengths, 8*12. (This shape is not to scale BTW) The area of the square is 144, and the area of the right triangle is 48, so the answer is 192 square units squared.
Another way of doing this is using the trapezoid area formula, which is
(b1 + b2)/2 * h. So 32/2 * 12 = 16*12 = 192.