Polygons - Explore the Possibilities
Objective
Big Idea
Opener
Remind students of their task, which is continued from yesterday's lesson Introduction to Polygons. They are to create polygons using the Interactive Polygon program, take a screen shot and paste that image into a Google Doc (Word doc, or other format) and then they need to write their observations.
Show the students how you, the teacher, will respond to their comments about the polygon drawing and prompt them to use more specific mathematical language.
Independent Investigation & Written Response
Now, students make a list of observations about the polygons they have created. The goal is to have them use specific mathematical language that will help them develop their understanding of polygons in general and the properties of certain shapes in particular. (MP6) To this end, their comments must be both clear and meaningful.
Examples of student comments:
Below Level:
- My shape has sides.
- Some of my sides are longer than others.
- All my shapes that I drew have 4 sides.
On Level:
- My quadrilateral has 4 angles and 4 sides.
- One angle in my quadrilateral is 114 degrees.
Above Level:
- I see that two of the angles in my quadrilateral are more than 100 degrees and two of them are less than 100 degrees.
- When I add all 4 of the angles in my quadrilateral together I get 360 degrees.
Polygon Tour - Debate & Dialogue
In this part of the lesson, I put students in an inside-outside circle (though in my classroom, it needs to be an inside-outside line!). They take turn interviewing a classmate using these Polygon Investigation Questions.
The objective is to solidify their understanding of different characteristics of polygons by supporting precise mathematical language (MP6) and their ability to support their thinking and critique the reasoning of others (MP3). I chose to have my students do this orally but their answers can also be written down on the Polygon Tour Recording Sheet.
Wrap-up
I call students together as a group and ask one or more of the following questions:
1. What is something new you learned today?
2. What is something you can explain now that you couldn't explain before?
3. Describe an interesting polygon that was presented to you by a classmate.
Remember, always insist on full sentence responses. Don't hesitate to throw in the prompt, "I know this because...". If students struggle to find the words, give them time to think before rushing to fill the silence. Allow the use of models (manipulatives, drawings) as an aid to explanations - it bootstraps the words. These practices are critical for developing thinking and language, not only oral but written as well.
