In the applet below, use the Point tool to plot ANY 4 points that serve as vertices of a parallelogram.
The only restriction you have on point-placement is this:
For all the 8 coordinates that will eventually be displayed, no coordinate can be displayed more than once.
That is, no repetition in coordinates is allowed.
Use the Polygon tool to construct your parallelogram.
Then, prove that your quadrilateral is a parallelogram in at least 2 different ways.

After successful completion of the exercise above, repeat this same exercise, yet this time change the word "parallelogram" (in the directions above) to "rectangle."

After successful completion of this previous exercise, repeat this same exercise, yet this time change the word "parallelogram" (in the directions above) to "square."