#MTBoS30: Central Angles and Arcs

Monday, May 16, 2016
I started off this lovely Monday morning with my projector being broke =( which means I had to go "old-school" and write on the white-board. I normally teach through my Mobi and walk around to  check students progress on the notes and correct behavior issues.

We started off the lesson by filling out this newly-created graphic organizer over basic terminology (students ended up referencing this more than the foldable).

I have used the following foldable for the past 2 years and I LOVE it because of how well students understand the naming and definitions of arcs. By this time in the year, students love to color code with me and their notes look very similar to mine (which always makes me smile). I went over the definitions and naming of the arcs and I gave students about 10-15 minutes to complete the middle diagram. After the time was up, I ended up cold calling on students to help me finish the foldable (less work for me :)).

After the foldable, I told students to create their own circle and to name and define a semicircle, minor arc, and major arc. It took students about 10 minutes to complete this graphic organizer and I will try to upload pictures soon of work samples because some students got very creative.

Once I checked their graphic organizer, I handed students the following homework assignment. The most missed question was #2 because they wanted to say it was a semi-circle.


  • This lesson went extremely well (especially since my preferred teaching method was out)
  • I seriously cannot think of one single thing that I would want to change :)

The files that I used today can be found here:


  1. I just found your blog and let me tell you- your resources are SO HELPFUL!! I am starting to get some materials together for next year, and I love your stuff - you are the sweetest for sharing it!! I have a quick question- do you have a pdf (or download) copy of the h.w. assignment for this? thanks in advance!

  2. I found your foldable on TPT and love it. Your blog will now be on my frequent stops list. Thank you so much for your willingness to share. I'm a veteran teacher but first year in Geometry and feeling a little overwhelmed so this helps!