Polygon Song & Lessons

Want to do a little polygon exploration?

1. Select a few ideas from our past polygon lessons.

2. Read Marilyn Burns' book, The Greedy Triangle.

3. Watch the following video. It's a perfect extension to The Greedy Triangle. This time, however, it's a square complaining about his life. Use the video with the book to do some "Paired Book" exploration...in this case, paired book and video exploration! :)

More Polygon Play! (Geometry Class #4, Fall 2010)

Time for some more polygon play...wanna play along?

I made a pdf (print it, free!) to review the terms for the number of sides of various polygons.

1. Print the sheet on white cardstock, one per person.

2. Have each child take a red crayon or colored pencil. As you say (or draw) the number of sides, they lightly color the rectangle with that term. Example: "Color in the word that means a 4 sided polygon." [Color in "quadrilateral."] After you've gotten through the first 8 terms on the sheet...

3. Now do the same thing in reverse. Have each child take a blue crayon or colored pencil. As you say one of the terms from the top of the page (already colored in red), they color in the card with that number of sides using blue. Example: "Color in the number of sides on an octagon." [Color in "8 sides."] Now everything should be colored in except the last two terms.

4. Do students know what "regular" vs. "irregular" polygons are? Review. If they don't, look here. Color the regular/irregular cards green.

5. Cut out cards.

6. Mix up cards. Match corresponding red and blue cards.

As you read the book, The Greedy Triangle, ask students to lay out the red and blue cards that match the polygon on each page.

Give children some popsicle sticks. Tell them to lay out the "triangle"  and "regular" cards. Ask them to make a polygon with those criteria. What do students notice about their polygons? Are they alike? Different?

 Ask them to lay out the "quadrilateral" and "irregular" cards. Make a polygon. Are their figures the same?

Ask students to set aside all cards except the following: triangle, quadrilateral, pentagon, hexagon, regular and irregular. Each child should select one card of each color (red and green) and lay it out in front of him. (Use the blue cards as needed if kids need reinforcement to recall how many sides are on each polygon.)

This is one awesome irregular pentagon. Dude!

Now, have kids switch places and build a polygon based on the cards at his new spot. Rotate around the table, placing cards, building, and checking polygons.

See our first Polygon Play session here. 

Look, Ma! Another irregular pentagon!

Captain, we are ready for irregular triangle takeoff!

Whoa. Irregular quadrilaterals are too cool for words.

P.S. The content in this post has been heavily influenced by Bridges lessons. Love them! :)

Reflective & Rotational Symmetry & More (Geometry Class #3, Fall 2010)

Another busy day with geometry! Here's what we did:

*read "A Square Puzzle" from Mathemagic. (This book, published in 1978, as part of the Childcraft series, has many interesting stories, puzzles, and activities. You can often find it cheap!)

*added to our "What Do You Know About Geometry?" flap books.

*shared symmetrical masks from last week, reviewed our understanding of "line of symmetry," and wrote definitions in a flap book.

*checked to see how many letters in our names are symmetrical.

*continued with lessons from Bridges, using an index card to investigate both reflective and rotational symmetry. We then explored symmetry with a variety of pattern blocks. I put a magnetic pattern block on the magnetic board, traced it, rotated, and asked the kids to stop me each time the block fit into the frame. They became very good at identifying the order of rotation and the number of lines of symmetry!

*read A Cloak for the Dreamer.

*used more Bridges lessons, building regular and irregular pentagons with toothpicks. Students followed up by drawing the shapes they made; this wasn't easy. (You try trying a regular pentagon!) We also built and drew regular and irregular hexagons.

*finished by building toothpick polygons. We'll use these next week.

Another great day! Thanks so much for all your hard work! :) If you'd like to do some "homework," check out the links below.







Great Resources for Further Study:

• Video on line symmetry 
• Investigating Symmetry in our Alphabet 
• Which capital letters have line symmetry?
• Symmetry Artist

Polygon Play (Geometry Class #2 Part I, Fall 2010)

Math class today. We did so many things that I'm going to break it into a series of posts. :)

Started with a brief review of tangrams by reading Grandfather Tang's Story. I provided tangrams so the kids could construct the animals as the story went along, but the story became too captivating...they slowly abandoned the pieces to fully concentrate on what was happening. Great book!

We continued with a review of polygons. Last week we discussed the characteristics of a polygon. I drew a variety of figures on the board and they told me which were polygons and which were not. Since we'd read The Greedy Triangle last week, we quickly flipped through the book to see the polygons used there.

We then made a flapbook...the word "polygon" on the outside of the flap and the characteristics listed inside. (This is not pictured.)

And now...to make a quiz for their parents...to see if they know about polygons. They LOVED that idea! We made a series of 6 flaps (see right photo...one flap is open.) I had them cut off the top flap to make a "title" area..."Is this a polygon?" They then drew 5 figures of their choice on top of the 5 remaining flaps. Under each, they wrote "yes" or "no" to indicate whether the figure is a polygon. They used rulers to make sure the straight lines were actually straight.

In the process of assessing their parents, this became a quick assessment to see if they had a solid understanding of polygons. With fun in the process!

Nice addition to polygon lessons:


Geometric Stick Lessons