Hey,
you have to draw a cordinate plane first. Start with the horizontal and write -6 --> 6 under it in equal distances from left to right. Then draw the vertical and start on the bottom with -6 -->...--> 6 up to the top.
The horizontal stands for the first number in A, B, C and D. The second numbers represent thevertical. In this order you mark the right spots and combine the four points in order to create a parallelogram.
I hope I could help you.