Answer:
8 square units
Explanation:
The "top" half of the trapezoid of height 4 with bases 3 and 1 can be cut off and added to the "bottom" half to form a parallelogram with a base of 4 and a height of 2. The area of that parallelogram will be ...
A = bh = 4·2 = 8 . . . square units.