A short instructional video by Florence explaining how to classify 2D polygons for primary pupils. It defines a polygon as a closed 2D shape with straight sides, describes classification by number of sides (e.g., triangles, quadrilaterals, pentagons), contrasts regular and irregular polygons (equal sides/angles vs not), and recommends classroom activities—presenting shapes in varied orientations, comparative tasks, and symmetry investigations (regular n-sided polygons have n lines of symmetry).
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Hi, I'm Florence, and in this video, we're going to look at some top tips for classifying 2D shapes and helping to avoid misconceptions. So, the most common shape that pupils look at is the polygon. And a polygon is a closed 2D shape made up entirely of straight sides. One way we can classify polygons is depending on the number of sides they have. For example, the triangle has three sides. Quadrilateral is a polygon with four sides. And it's really important when you're presenting these images to pupils that you present them at a variety of angles and orientations. This presence prevents pupils from having the misconception, for example, that a triangle must always be upright. Being able to classify shapes is about being able to recognize the similarities and differences between them. So one activity I like to do with my pupils is provide them with two or more shapes and ask them to discuss what's the same and what's different. In this example, they might identify that they both have five sides. So what's the same is they're both pentagons. What's different is the lengths of the sides are the same. In this shape, they're all equal, whereas they're different in this pentagon. And the angles in this pentagon. Again, the internal angles are all equal. The internal angles in this pentagon are different. So this brings about a second way that we can classify polygons, which is as regular and irregular. A regular polygon has sides that are all equal in length, and all the internal angles will be the same as well, whereas an irregular polygon doesn't meet this criteria. And if we think back to these images that I presented at the beginning, we can see again, I've tried to use a variety of regular and irregular polygons to really help pupils and avoid those misconceptions. A good investigation to set pupils is to see if they can explore the lines of symmetry in regular and irregular shapes. So, for example, they will find that in regular polygons, the number of sides that the shape has will be the same as the number of lines of symmetry they find. That's why in this equilateral triangle, we have three lines of symmetry. So those are some ideas for how you can help children to classify 2D shapes and also to make sure they don't have misconceptions about what 2D shapes look like.
