Answer:
21 square units.
Explanation:
The area of a parallelogram is just the base times height.
In this case, the base is 3, as the height is 7, so the area of the parallelogram is 21 square units.
Another way you could try solving this is by sliding the upper triangle down, and you'll end up with a rectangle, with side lengths 3 and 7. Multiplying this out gives us a final area of 21 square units.
Let me know if this helps!