Lines of Symmetry Worksheet (Free KS2 Butterfly Printable)

What a line of symmetry actually means

A line of symmetry is a line that divides a shape into two halves that are exact mirror images of one another. If you could fold the shape along that line, the two parts would sit exactly on top of each other. A butterfly held straight on has a vertical line of symmetry running down its body: the left wing is the mirror image of the right. Helping a child see this matching relationship, rather than simply memorising the phrase, is the foundation for the rest of the topic. Encourage them to check by imagining the fold, or by holding a small mirror along the line and seeing whether the reflection completes the shape.

How this fits the Year 4 maths curriculum

In the National Curriculum for England, Year 4 pupils are expected to identify lines of symmetry in 2-D shapes presented in different orientations, and to complete a simple symmetric figure with respect to a specific line of symmetry. Children first meet line symmetry in Year 2, where they look for a vertical line. This worksheet practises that vertical case thoroughly: children draw the line of symmetry themselves, colour so that one wing still matches the other, and test whether a horizontal line would also work (it would not). Because the butterfly is shown in only one position, Year 4 children should go on to shapes turned at different angles. Once they are confident here, you can extend the work to squares, rectangles, triangles and letters, some of which have more than one line of symmetry and some of which have none.

Making symmetry concrete with everyday objects

Symmetry becomes much easier to grasp when children connect it to things they already know. Point out the symmetry in a leaf, a face, a snowflake, the front of a house, or the wings of a real butterfly. A practical test is to fold a piece of paper, cut a shape from the folded edge and open it out: the fold line is automatically a line of symmetry. A small handheld mirror is another excellent tool, because placing it on a line of symmetry shows the complete shape, while placing it anywhere else does not. These quick activities reinforce the idea that a line of symmetry is special, not just any line through the middle.

Using this worksheet at home or in class

For colouring, set the expectation early that matching shapes on the two wings should be coloured the same, so the finished butterfly stays symmetrical. This turns a simple colouring activity into a deliberate test of understanding. The written questions can be completed before or after colouring, and they are short enough to use as a starter or a plenary. To stretch a confident child, ask them to draw their own butterfly and add a second pattern that is symmetrical, or to find letters of the alphabet that have a line of symmetry. To support a child who is finding it tricky, offer a small mirror to place down the body line so the matching halves become obvious.

Frequently asked questions