9514 1404 393
Answer:
20 square units
Explanation:
The area is given by the formula ...
A = bh
where b is the base of the parallelogram, and h is the perpendicular distance between the parallel bases. Using the numbers from the figure, we have ...
A = 5·4 = 20 . . . . square units
_____
Additional comment
You will notice this is the same formula as is used for a rectangle. You can consider the parallelogram to have the same area as a rectangle of these dimensions if you look at what happens when you cut the right triangle from the right end and add it to the left end. The result is a rectangle 5 units wide and 4 units high.
The same formula applies even if the skew is so great that the bases do not overlap. (That much skew would not result in a triangle of the kind shown in this diagram.)