Answer:
6 square units
Step-by-step explanation:
In the attached drawing, we have drawn a green line across the figure one unit down from the top.
The red parallelogram above the green line has an area of 1. It is one unit high and one unit wide.
The area of the rectangle below the green line is 12: it is 4 units wide and 3 units high. The diagonal from lower left to upper right divides that rectangle in half, so that the bottom right triangle and the upper left triangle both have an area of 6. The shaded area of the upper left triangle is smaller than 6 by the area of the unshaded triangle that intrudes into the space.
That unshaded triangular intrusion has a base of 2 and a height of 1, so an area of (1/2)(2)(1) = 1. Then the red shaded area below the green line is 6 - 1 = 5 square units.
Altogether, the red shaded area is 1 + 5 = 6 square units.
