What do you see going on here? What do you wonder? Notice anything interesting? If so, describe.
Were you able to make the plane disappear in the app above? If so, what causes this to happen? Describe.
What do you notice about O and its reflection O'? Describe as specifically best as you can.
Now drag point O [i]onto the plane itself[/i]. You may need to reposition the plane to do effectively do so. If point O lies on the plane, where does its reflection lie?