Tips for Teaching Angles

Why do learners struggle to measure angles using a protractor?

My Year 5 maths learners started the angles chapter with good prior knowledge of the names and specifications of angles. This stood them in good stead for Lesson 1: Knowing Types of Angles.

But my class hit a speedbump in Lesson 2: Measuring Angles which focused on measuring angles within a polygon. The pace of the second lesson was fast, and it was clear that not all learners were making ‘expected progress’.

Digging deeper, I could see that the practical skills needed to use a protractor to measure angles were causing confusion in my class. Children seemed to struggle to understand the difference between the ‘inside’ and ‘outside’ scales of the protractor and confused reflex and obtuse angles.

I realised that to address this, I’d have to break down the steps of measuring angles and slow things down for learners struggling with this aspect of the topic.

How to measure angles: a step-by-step guide

In the next lesson, I wrote down the steps of how to measure the angles on my whiteboard:

1. Find the baseline of the protractor and line it up with the baseline of the shape or angle
2. Place the midpoint of the protractor on the vertex of the angle
3. Line up one side of the angle with the zero line of the protractor (where you see the number 0)
4. Read the degrees where the other side crosses the number scale

After reading these instructions to my class, I decided to pop on my handy visualiser and told them we would be re-measuring all polygons from our workbook following the step-by-step instructions on the board. My learners moaned but I repeated my instructions until eventually everyone was on task and engaged in making corrections in their workbooks themselves.

Following that 20-minute recap, I felt the class could move on to the next lesson with greater confidence (as I had previously planned).

The third lesson set my learners up for even more angle-measuring practice and gave them some slightly more accessible shapes to measure. They also had the opportunity to measure angles on a straight line. This was something they really enjoyed, and they were keen to start using their newly-found protractor skills.

What angle measuring resources can you use to teach angles?

Resources are always helpful for my class, especially if they are visual. To assist my learners in their understanding of angles, I have printed out and displayed the names and characteristics of the different types of angles with corresponding pictures.

We’ve also spent time examining our classroom and identifying how many right angles we can see. This visual aid has supported learners in their protractor-measuring journey.

I’m constantly reminding my class that angles are all around us! Another challenge I set was to find how many different types of angles they could find in everyday life outside the classroom: corner joints on furniture, corners of rooms, foil-wrapped cheeses, or indeed, straight lines.

At first, teaching angles proved to be difficult for some learners to access. But in the end, it provided them with an invaluable opportunity to see how angles are an intrinsic and important part of the real world.