**What is reflective symmetry?**

Reflective symmetry is when a shape or pattern is reflected in a **line of symmetry** or a mirror line.

The reflected shape will be **exactly the same** as the original, the same distance from the line of symmetry and the same size.

**What is a line of symmetry?**

Lines of symmetry are imaginary lines that can be drawn on two-dimensional shape, where the image on either side of the line **matches exactly**.

Where lines of symmetry are drawn on shapes, they are usually represented as a **dashed line**.

**e.g. Are these lines of symmetry?**

Imagine that we could fold the square along the dashed line - would both halves of the shape fit perfectly over each other?

If so, then we have **a line of symmetry**.

In the case of the square, they do perfectly match, so the line of symmetry shown here **is correct**.

With the triangle, the shapes on either side of the line are **not the same**.

Can you see that the triangle on the left of the line is smaller than the one on the right?

So, the line of symmetry shown on the triangle** is not correct**.

**e.g. How many lines of symmetry does the following shape have?**

This has shape two elements - the outer square and the letter A.

A square has **4 lines of symmetry**, whilst the letter A has **1 line of symmetry**.

When we have two elements present, the** lowest** number of lines of symmetry is the one we need to use.

So in this case, we have **one line of symmetry **on the combined shape, shown here:

**e.g. How many lines of symmetry does the following shape have?**

This example is actually easier than the last one.

This is a **regular hexagon**; remember that 'regular' means all the angles and sides are the same.

When we have a regular shape, the number of lines of symmetry is **the same as the number of sides present**, so this shape has **6 lines of symmetry**, shown here:

In this activity, we will identify valid lines of symmetry and define if and where they occur in a range of regular and irregular shapes. We will also use the logic that the number of lines of symmetry match the number of sides present to solve related problems.