a. A parallelogram has a base of $3.5$ units and a corresponding height of 2 units. What is its area?
b. A parallelogram has a base of 3 units and an area of $1.8$ square units. What is the corresponding height for that base?
c. A parallelogram has an area of $20.4$ square units. If the height that corresponds to a base is 4 units, what is the base?