The heigt of a parallelogram is the product of the length of its base and its height.
The height of a parallelogram is the distance between the base and the side parallel to the base.
If we take the segment JC as the base of the parallelogram, then the height has a measure of 7 units and the base has a measure of 6 units, as shown:
Calculate the area of the parallelogram by multiplying its height and its base:

Therefore, the area of the parallelogram shown in the coordinate plane is 42.