Students: Of course!
Student 1: I'll do it! (Walks to the white board)
Me: (to the class) What do we think? Is that red point in the same plane as the others?
Students: Yes, they're still coplanar. They're on the same white board.
Me: Does someone else have an idea about how to make non-coplanar points?
Student 2: Put a dot on the other white board.
Me: Even though they're on two separate boards, a plane keeps going forever, so these points are still coplanar. Can anyone think of where to put a point somewhere in this room that isn't coplanar with the others?
Student 3: Put a point on the other wall.