The sketch of the parallelogram is attached
How to show the sketch is a parallelogram
The length of opposites sides of parallelogram are equal. Also, are the slope of the lines.
The slope calculation
Slope of AB
= (2 - 0) / (5 - 0) = 2/5
Slope of CD
= (4 - 5) / (1 - 6) = 1/5
Since, slope of AB = slope of CD, AB is parallel to CD.
The lengths of AB and CD:
Length of AB
AB =

length of CD:
CD =

Since AB = CD, AB is equal in length to CD.
Therefore, we have shown that opposite sides AB and CD of ABCD have the same slope and are equal in length, which means ABCD is a parallelogram.