Understand Reflections in Straight Line Graphs

In this activity, we will look at reflections in a straight line graph.

A reflection is a transformation. 

For a shape to be reflected the two shapes must be:

1)  the same size

2)  the same distance from the mirror line

3)  facing opposite directions ('flipped')

To reflect in straight lines on a grid we have to be familiar with the most common straight lines used!

Vertical lines:   x = something

Horizontal lines:  y = something

Diagonal lines:   y = x   or   y = -x

We put the straight line graphs together with the reflections.

Let's look at a typical question!

Example

Reflect the shape below in the line x = 2 

Answer

We identify the mirror line first.

 x = 2  is vertical and cuts through x = 2

Next, we count how many squares each corner is from the mirror line and plot the same distance on the other side.

Do this for all four corners and join together to form the reflection!

Have you got it? Let's try some questions.