The Greedy Triangle Activities

We had quite a bit of fun playing with, and eating, tetrahedrons over the weekend. But, I thought before we went any further with three dimensional shapes, we should backtrack for a quick look at two dimensional shapes.

I've seen the Greedy Triangle by Marilyn Burns, recommended a number of times around the blogosphere, and thought it might be a good place to start. It's the story of a discontented triangle, who thinks his life could be more interesting if he just had one more side, and one more angle. So, with the help of a shape shifter (a shapeless blob, in a wizard's hat), he explores life as a quadrilateral, hexagon, heptagon, octagon, and nonagon, before finally deciding he likes his life best as a triangle. I found it a tiny bit monotonous, but the children were riveted.

If you can't get a hold of a copy of the book yourself, you can watch it being read, library story time style, here, on School Tube.

There are a number of online lesson plans available to go along with the book, too. Superheroes and Princesses has a companion art idea, Chronicle of an Infant Bibliophile, has a printable play along shape activity, and Mouse Grows, Mouse Learns has a shape craft suggestion. I also came across a couple of sites suggesting the use of a geoboard, for exploring shapes along with the story.

Since, we've recently seen all the fun K, over at Joyful Learner has been having with her geoboard, I decided that was the way to go. We don't have a geoboard on hand, so I crafted a quick one, using a thick piece of Styrofoam, that came in the packaging of one of our Christmas presents, a bunch of screws, and a few pot holder loops.

Ideally, a person would use nails hammered into wood, but I didn't have a piece of wood, or enough nails on hand, so I went with what I did have. I measured out a quick, one inch grid, on the Styrofoam, stuck the screws in, at each intersection, tossed out a few loops, and we were good to go. Actually, the children started playing with it, before I could even get all the screws into place.

This type of construction would not be good for permanent play, or for toddlers, since the screws can be easily pulled back out, but it worked as a quick solution for us, in a pinch. The children like it well enough, and I can see enough future teaching potential with it, that I think we'll definitely be looking into making a sturdier version.

While the younger children were busy playing with the geoboard, making shapes, and stories, I also cut them out a set of geometric lacing cards, from fun foam.

I used a small printout of the shapes, as a guide for the angles, but I increased the sides.



Then A, punched two holes on each of the shapes' sides...



...so after the younger girls laced them with shoe laces...



...they could easily, count the sides of the shape, on one side...



...and the number of corners, or angles, on the other.


Again, you can find more math themed activities, and ideas, at this week's Math Monday link-up, hosted by Joyful Learner.

It's great to be a homeschooler.