Sides and Corners of 2D Shapes
Year 2 count and describe the sides and corners of 2D shapes.
# Sides and Corners of 2D Shapes
Once children can name simple shapes, the next step is to describe them. Counting sides and corners helps children sort shapes and notice what makes each one special. This lesson builds the vocabulary children need to talk about shapes with confidence.
What Is a Side?
A side is a straight line that forms the edge of a shape. A triangle has three sides, a square has four and a pentagon has five. A circle has no straight sides, only one curved edge, so we say it has no sides in the usual sense.
What Is a Corner?
A corner, or vertex, is the point where two sides meet. The plural of vertex is vertices. A square has four vertices and a triangle has three. Counting vertices is a quick way to check a shape because the number of sides and corners usually match.
Regular and Irregular Shapes
A regular shape has all its sides the same length and all its angles the same size. A square is regular because every side and every corner is equal. A rectangle is irregular because its sides are not all the same, even though its corners are right angles.
Sorting Shapes
Give your child a set of shapes and ask them to sort them by the number of sides. This builds the habit of looking closely. You can also sort by the number of corners or by whether the shape has any right angles.
Real World Shapes
Look for pentagons on footballs and hexagons in honeycomb. Finding shapes in real life shows children that geometry is not just a classroom subject. It is a way of understanding the world around them.
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