blog reboot and getting outside

I'm trying a reboot of my blog. My goal is to keep posts short, update what is going on with what I'm doing as a teacher and to make up for the years of blog posts that I spewed disgusting technology and data focused ideas...

This year I've made it a goal to get students out of the classroom on a weekly basis to see the math that we are learning appearing in the world around us. 

We walked the perimeter of the school grounds which I learned (after being here for 14 school years) is actually about a mile. Our shoes got wet but we now have a good memory to connect with perimeter!

We went into the cafeteria to find the area and that looked like counting floor tiles and subtracting areas of the room that had closets or protruding sections of wall. 

We went outside to look for right triangles and determine if objects being measured represented right angles.

I'm finding the students are enjoying getting out to be active and the more often we do this I'm able to see the students' creativity in finding ideas present I wouldn't have thought of. 

Polygon angle sum theorem and the distributive property

We did this in class today as a warmup activity. I've always led students toward the first example but we made kind of a cool connection to the distributive property when we tried to make a student's picture work when they drew the triangles from the center of the figure instead of from a vertex.

In the first example all angles in the triangle add to the total measure of the polygon.

In the second example, the interior angles for the triangles (center) do not make up any of the polygon interior angles so we subtract them. To make the connection rather than writing it as 360 I wrote it as 2•180.