Last week I was working with a fourth grade class that was exploring geometric solids. They were asked to do a scavenger hunt in the classroom to find examples of each different solid – square and triangular pyramids, cylinders, cones, cubes, spheres, and rectangular and triangular prisms. Naturally, there were plenty of rectangular prisms (books, boxes, etc.), but some of the other shapes were really hard to find. The one we didn’t find any examples of was a triangular prism. Being the innately curious person that I am, I really scoured the room for anything that resembled a triangular prism. All I came up with was the one from the geometric solids manipulative bin. The only real-life triangular prism I could think of was the box from a Toblerone bar…chocoholic that I am! Determined to find some non-edible form of triangular prism in real life, I turned to my Twitter network. Over the last year or so, I have been communicating regularly with a group of math teachers, coaches, and university professors on Twitter. We exchange ideas, brainstorm, problem solve, and share great articles and books with one another. In a desperate plea for help, I sent my request out to the “Twitterverse.” Here is the conversation that ensued…

@GPSMathCoach – “Need real-life examples of triangular prism for Gr. 4 geometry lesson. All I came up with was a Toblerone bar! Ideas? #mathchat #edchat”

@delta_dc – “What about a pup tent?”

@GPSMathCoach – “Knew I could count on you…but was hoping for something I could show in class w/o moving furniture. :)”

@ColinTGraham – “Toblerone! ooh, thinking of chocolate now…”

@delta_dc – “Aren’t there any Playskool or Playmobil tents you could use?”

@ColinTGraham – “If you don’t mind a curved edge – cake slices, or wedges of cheese. Frame for a garden swing, maybe”

@GPSMathCoach – “Will check out Target tomorrow.”

@delta_dc – “Just checked online – nothing. But here’s a pic.”

So…as you can see, with the wealth of resources I have at my disposal I managed to get two people engaged in the conversation, and one “real” suggestion, which I couldn’t get my hands on before class the next day.

When I walked into class in the morning, I took my big Toblerone bar to the front of the classroom, and I used this whole experience as a learning opportunity. I told the kids that sometimes no matter what you try, there aren’t any really good answers out there. In my quest to find a real-life triangular prism for them, I had Googled, Tweeted, and even shopped. All I came up with was the original example I had thought of to start with – the Toblerone bar. I think we all learned a lesson. Sometimes a problem doesn’t have an easy answer, and sometimes it’s hard to connect math to real life. That doesn’t mean I will stop trying…and I let the kids know that they should take the same stance. Plus, a Toblerone bar makes a pretty tasty triangular prism.

I was and still am scouring the web for a 9th grade real-life example of triangular pyramid and toblerone did occur to me. However, I eventually realized that toblerone isn’t actually a triangular pyramid, it is a triangular prism. Correct me if I’m wrong but isn’t a triangular pyramid a 3D shape that has a triangular base and 3 congruent triangles that meet at the top of the pyramid? Toblerone has a triangle base but the other faces are rectangles not triangles.

This post was about triangular prisms, not triangular pyramids. You are correct about the difference between the two, however.