Thursday, October 6, 2011

Quarter-Turn Corners

We've been learning about quarter-turn corners.
We also call quarter-turn corners  right-angles.
We found out that squares and rectangles have quarter-turn corners, so we used these shapes to test other corners in the classroom.
This is what we found:

We also found corners that are NOT quarter-turn corners. Some were too big and some were too small!

Look around you - where have you noticed some quarter-turn corners (right-angles)?

For older children - what are the names for the angles that are bigger than right-angles and the angles that are smaller than right-angles?


  1. Mrs McKenzie and B4
    I really like the fact that your students created two seperate slideshows, that was really interesting because once you watched one all the way through and then the other you really got to know the difference between the two. Even though I am a very old teacher I can't recall having right angles called quarter turn circles before so I had a smile when I read what they were, even at my old age I was able to learn something today so thanks B4 for teaching me, and that's something that I will be able to share with my students.
    Mr Webb and Room 8, Melville Intermediate School, Hamilton, Waikato.

  2. Dear b4

    I have a quarter-turn corner in my house it is the table and I have a not quarter-turn that is Mum and Dads bed

    your :)
    from Ganda

  3. Thank you for sharing your quarter turn corners with me. I like that ideas of quarter turn as it is also a fraction so you learn more than just one thing. Like Mr Webb I have learnt something new from you today as well. I think I will share this with my children.

  4. Dear B4

    Just dropping by to let you know that we received your postcard today. It was very exciting to read it and look at the picture on the front that showed us your town location. Your postcard is the first one we have received and we are going to put it up on our map wall with a string to show which country it is from.


    Mrs S and 4DS

  5. I enjoyed the videos on quarter turn corners. I find it very interesting how different schools use different language. In Connecticut where I teach we use the term square corners when we refer to right angles. Sandi's comment above helped me to understand that a quarter turn was related to a quarter in fractional terms. I think I'll tell my students about the term quarter turn this year as we work on our square corners. How did your teacher explain them to you?
    -Mrs. P

  6. Dear B4,

    Hello, we are the Techie Kids from Michigan, USA. We are a second grade class that meets on Tuesday. It looks like you worked very hard on the videos you made. You found a lot of quarter-turn corners. We are used to hearing right angles. It's fun to learn new things. We liked figuring out which angles were too big and too small. We also really liked the music.

    We found some quarter-turn angles in our classroom too. We found the corner where our walls meet. We see the corners of our posters, the whiteboard, the ceiling tiles, the corner of the computer screen, and the corner of the rug.

    We have 27 students in this class. How many children are in your class?

    We hope to hear from you soon.
    Mrs. Moore and the 2nd grade Techie Kids

  7. Dear B4,

    I found it very interesting that you call these quarter turn corners. It makes total sense but we always just call them right angles! It's funny how in different countries they are called different things!

    It looks like you found plenty of quarter turn corners! They are all over the place. Just looking around my house right now I see plenty of them. I see them in pictures on the wall, on our coffee table, in the windows, and on the TV.

    Keep up the great work!

    Mr. Avery

  8. Dear Mrs. McKenzie and B4,
    Thank you so much for sharing your videos and for teaching me something new! Like some of the teachers in the previous comments, I too have never heard the term quarter-turn corners.

    Here in British Columbia we refer to them as right angles. I think "quarter-turn" makes a lot of sense. I'll be sure to share this new math term with the grade 2/3's when we study geometry.

    Your friend,
    Mrs. W