Answer:
13 square units
Step-by-step explanation:
The bounding rectangle is 4 units wide and 5 units high, so has an area of 4×5 = 20 square units. From that are subtracted the areas of 4 triangles. 2 of them are 3 wide and 1 high, so have a combined area of 3×1 = 3 square units. The other two are 1 wide and 4 high, so have a combined area of 1×4 = 4 square units.
Then the area of the parallelogram is ...
20 -3 -4 = 13 . . . . square units
