Answer
$A: 0,0 \\ B: 2b,2c \\ C: 2a+2b, c \\ D: 2a,0$
Work Step by Step
An ideally placed parallelogram, which we will call parallelogram ABCD, should have point A placed at the origin and side AD be on the x-axis. Calling the length of AD 2a and the coordinate of point B (2b,2c), we obtain:
$A: 0,0 \\ B: 2b,2c \\ C: 2a+2b, 2c \\ D: 2a,0$
Note, there are twos in front of all of the numbers because the book asks for midpoints, and we have to account for the fact that the midpoints are half of these numbers.
