Class make-up work:
Watch the nonagon song, and as you watch it, think about these questions:

• what are the definitions of the shapes named in the song?
• what shape definition is different from the others?

Watch our class discussions about these shape definitions:

• beginning discussion
  
• draw 3 triangles on a piece of paper, and then watch: triangles
  
• other shapes

Brainstorm a list of all of the names of 4-sided shapes you can think of, and then watch our class discussion (post brainstorming):

• Discussion of quadrilaterals

Think about the question at the end of the previous video (what sorts of shapes do you see in early elementary classes, and how do you think that affects how children think about shapes)?

• Discussion of 4 shapes

Brainstorm by yourself for 3-4 minutes and then watch:

• teaching ideas discussion

Make or find a square piece of paper, and watch this lesson and follow along with it:

• Go to http://learner.org/resources/series32.html and watch lesson 20: Shapes from squares.  Pause after the teacher gives instructions to the class, and do the activity yourself before you watch what the class did.  You may stop at the end of the lesson--you do not have to watch the commentary.