Saturday, March 4, 2017

Right Angles Made Easier

Right angles are HARD to teach, am I right?! Here are some strategies we use to try to make it a little easier. First, we like to show them the corners of a square and have them position their arms in the same directions. Then we show them how *not* to make a right angle. No “Yay!” arms (an acute angle with both hands up toward the ceiling) and no “Ta-da!” arms (an obtuse angle with arms out to the sides).

After some explicit teaching about shapes that do and don’t have right angles, we use Morgan Clark’s memory game.
We’ve also shrunk it down and added headers to use as a sort for students to glue the shapes onto. This gives you a good idea of who can remember and identify shapes that have right angles.

Then we created this worksheet for students to count how many right angles a shape has and draw shapes with a given number of right angles: tricky skills to master.

Finally, we have these handy-dandy right angles.
My fantastic inclusion teacher pointed out how hard it can be for some students to align a book/index card/paper accurately with an angle to determine whether or not it is a right angle. Not only do they put their tool on the outside of the shape but they also can’t see both sides of an acute angle. These right angles were traced onto scraps of lamination. I also traced an oversized right angle for me to use during for whole class instruction. These tools have only three rules. 1: You must put the vertex of the right angle on top of one of the vertices in the shape. 2: If the right angle closed it would eat part of the shape. 3: One line of the right angle must be on top of on of the sides of the shape. This year when my students completed the “Right Angle Identification” worksheet, the class average was 53%. Yikes. After I showed the class how to use their new lamination tools, the average went up to 92%. That’s without any re-teaching, just a new tool. Color me impressed.


  1. I wish you were right about Virginia removing right angles from the first grade standards. It really is a concept they have trouble grasping at this age. However, you may want to look at SOL 1.11a again. You will find right angles in the essential knowledge and skills section of the curriculum framework. Unfortunately, we still have to teach them.

    1. I actually just started my shapes unit and discovered that sad fact as well. =( They removed "right" from the wording of the standard but it is definitely still included in the framework! Adjusting my post now.