What is the area of a parallelogram whose vertices are a(−1, 12) , b(13, 12) , c(2, −5) , and d(−12, −5) ?

238 square units. The area of a parallelogram is the base multiplied by the height. You can use any of its four sides as the base, so pick the one that is easiest to deal with. Examining the parallelogram, you'll notice that line segments AB and CD are both parallel to the x axis which makes it extremely easy to calculate the height which is 12 - (-5) = 17. The length of AB is 13 - (-1) = 14. So the area of the parallelogram is 14 * 17 = 238