Looking at the first two vertices, A and B, we see that the x values have a difference of (-1 - 13) units, or 14 units. This gives us the base of the parallelogram. Next, we look at the difference between the y values between B and C to find the height. In this case, they are (12 - [-5] ) units, or 17 units. The area of a parallelogram is simply base multiplied by height, which is (14 * 17), or 238 square units.
