Understand How to Reflect Shapes in a Mirror Line

In this activity, we will learn to identify shapes that have been reflected in a mirror line. 

 

When we reflect a shape, it appears flipped, like a mirror image.

The mirror line is often marked using a dotted or dashed line.

 

Look at the following L-shapes drawn on x and y-coordinate axes.

 

When we reflect a shape in a mirror line, we reflect each corner in turn.

This is done by moving each point directly to the mirror line and then the same distance beyond.

Shape A and Shape B are reflections of each other in this vertical mirror line.

 

Let's try an example together.

 

Example

Is the mirror line used to reflect shape A to shape B, vertical or horizontal?

 

 

Answer

In the following example, the mirror line is horizontal.

The same technique is used to reflect the shape.

 

Now it's time for you to have a go at some questions.