Answer:
C. 18 square units
Step-by-step explanation:
The bottom edge is horizontal, so its length is easily determined to be 6 by subtracting one end-point x-coordinate from the other.
Similarly, the height is easily determined to be 6, as that is the difference between the y-values of the base line and the opposite vertex.
The area is half the product of these dimensions:
A = (1/2)bh = (1/2)(6 units)(6 units) = 18 square units
