The Friday Fave is enjoying the fresh crop of apples and a few changing leaves
this week. And the Fave’s mind is turning to hexagons.
Polygraph: Hexagons, Part 2
At teacher.desmos.com, we have a small collection of “Part 2” activities—these are activities that follow up on and help to formalize ideas that got started in one of our Polygraphs, or in Function Carnival.
In Polygraph: Hexagons, Part 2, students do a variety of things, and produce a variety of results, in a small number of screens. For example:

They interpret the meaning of an informal term, and learn the
relevant formal vocabulary.
 They clarify an ambiguous use of “symmetry”.
 They sketch a concave hexagon.
 They draw in lines of symmetry.

They speculate on the existence of a hexagon with a line of symmetry,
but not rotational symmetry, and attempt to sketch one.

They clarify a common misinterpretation of “right angle”.
When an activity has students building arguments and imagining new mathematical objects, it’s likely to be some kind of Fave here at Desmos (Friday Fave or otherwise).