# Day 104: Construction Projects

I was down for the count yesterday… There are various colds and forms of the flu going around school and I came across one of them; so yesterday there was no post. I am feeling better today and wanted to share geometry’s finished construction projects.

A quick rundown of the project:

First I asked them to recreate a few designs out of a packet of 50 so. Then, I challenged students to mess around with inscribed penta/hexagons and get creative in various intersections and arcs. In all, they had about two days in class to work on them plus a weekend. I am pumped about their original creations…

Lots of other great ones as well!

# Day 91: Polygons

Geometry started talking about polygons today.

I broke the class into groups and had them sort these polygons from least to greatest number of sides:

Every group had the first 8 or so correct. After that they were everywhere. There were some interesting discussions on what polygon had the most sides and what that number was. Some said 20, other said 90.  Also, some great discussion on how to sort/classify.

After, they started working towards discovering the Polygon Angle Sum Theorem

They copied down the table and started working. Again, some very interesting discussion/methods of completing the table. Some based it on recursion others saw it as linear.

In the end everyone settled on 180(n-2). Why this worked though was another story. Eventually they got it and found out (n-2) is the number of triangles each polygon can be broken into.

For example

Today was a lot of fun, it sure beat just telling them the rule and practicing 30 problems after.