Friday, July 18, 2014

#July2014Challenge: My Favorite Unit Circle

Today is only my 4th day of the July blogging challenge (initiated by Druin at, and I already feel like I need a break.  One of my goals in starting a blog is to improve my writing skills.  Writing does not come naturally to me, so this takes time and effort.  I wanted a short and sweet blogpost for Friday, and after checking out what others were writing about I found #MyFavFriday.  So here it is!

This is a unit circle made from 4 pieces of cardstock and a brad.  The special right triangles rotate around the origin so that you can see the reference angle that you need for each of the angles listed on the circle.  I used to make this unit circle with all of my trig classes, and I found that many students still had it the next year for calculus.  I always make a few extra and stick them on the whiteboard with a magnet, and they get used constantly by my calculus students.  It is hard to tell from the picture, but each special right triangle has all of its angle and side measures printed, and the red circle is about 7 inches in diameter.

You can buy a kit to make this circle for $12 at Facing Math. The kit includes directions for making the circle as well as two practice worksheets with trig ratios that are way better than what I found in my textbook. Cardstock and brads not included, but still worth every penny!


  1. Ekk.. I think BlogSpot just ate my comment! :) The July Challenge has been tough for me too. In fact, it's one of the hardest things I've done in my life. The first few days were okay, but Days 4-12 were horrible! It did get better though! Keep it up!

    1. Thanks so much for the encouragement. Not only is it tough, it's also kind of scary to put your work in front of a potentially big crowd. After lots of blog reading though I have come to see this community as kind and supportive, which made all the difference in helping me to take the leap into MTBOS.