Answer: The coordinates of point D would be (2,6), I believe.
Step-by-step explanation: This is because you need four corners, and in order for it to be a rectangle it needs to look something like this:
* *
* *
or
* *
* *
Using the coordinates given, it'll look something like this:
*(?,?) *(5,6)
*(2,1) *(5,1)
We know that (2,1) and (5,1) will be together because they are both up 1 unit on the y-axis. In order for it to be a rectangle we need two level sides of the same length. We need to find a point that will be level with (5,6). Since the other point is (2,1), we know the x-value must be 2. Therefore, the missing point, Point D, is (2,6).
