A transformation is a process that may change the size, orientation or position of a shape.

A reflection of a shape is the mirror image of the shape. An object is reflected when it is flipped over a fixed line (line of reflection), without the image being turned or its size changing.

The line of reflection is the fixed line about which an object is reflected. The object and image are equidistant from the line of reflection.

The object is the starting figure, before a transformation has been applied.

The image is the resulting figure, after a transformation has been applied.

Checking and securing understanding of reflection

Maths

In this unit, pupils enhanced their understanding of enlargement. In this future unit, pupils investigate the effect of an enlargement on the perimeter and area of a 2-D shape and the volume of a 3-D shape. 

In the prior unit, pupils learnt about the different types of transformations. In this unit, pupils' knowledge is extended as negative scale factors are considered as are multiple transformations.

Further transformations

A reflection of a shape is the {{ }} image of the shape.

Which of these diagrams show a reflection?

Shape A is reflected onto shape B. What is the equation of the line of reflection?

A translation by the vector $$\begin{pmatrix} 3 \\ -3 \\ \end{pmatrix}$$

A rotation of 180° clockwise about the origin

The point $$P$$ has coordinates $$(3, -2)$$. $$P$$ is reflected in different lines of reflection. Match the coordinates of the image of $$P$$ to the equation of the line of reflection.

A translation is a {{}} in which every point of a shape moves the same distance in the same direction.

$$\begin{pmatrix} -4 \\ -5 \\ \end{pmatrix}$$

$$\begin{pmatrix} 4 \\ 5 \\ \end{pmatrix}$$

$$\begin{pmatrix} -5 \\ 4 \\ \end{pmatrix}$$

$$\begin{pmatrix} 5 \\ -4 \\ \end{pmatrix}$$

$$\begin{pmatrix} -4 \\ 5 \\ \end{pmatrix}$$

$$\begin{pmatrix} 5 \\ 4 \\ \end{pmatrix}$$

Match each description to the correct vector.

The point P(4, 3) is translated by the vector $$\begin{pmatrix} -2 \\ 1 \\ \end{pmatrix}$$ to P'. What are the coordinates of P'?

Translation by  $$\begin{pmatrix} -3 \\ 2 \\ \end{pmatrix}$$

Translation by  $$\begin{pmatrix} 3 \\ -2 \\ \end{pmatrix}$$

$$\begin{pmatrix} 2 \\ 3 \\ \end{pmatrix}$$

$$\begin{pmatrix} -2 \\ 3 \\ \end{pmatrix}$$

$$\begin{pmatrix} 2 \\ -3 \\ \end{pmatrix}$$

Shape P is translated onto shape Q by the vector $$\begin{pmatrix} -3 \\ 2\\ \end{pmatrix}$$. What transformation will map shape Q onto shape P?

B is translated by  $$\begin{pmatrix} 0 \\ 2 \\ \end{pmatrix}$$ onto C

C is translated by  $$\begin{pmatrix} 1 \\ -2 \\ \end{pmatrix}$$ onto D

D is translated by  $$\begin{pmatrix} 1 \\ 3 \\ \end{pmatrix}$$ onto E

E is translated by  $$\begin{pmatrix} -1 \\ -1\\ \end{pmatrix}$$ onto F

F is translated by  $$\begin{pmatrix} -7 \\ -2\\ \end{pmatrix}$$ onto A

This lesson will be removed by end of Summer Term 2025.

Checking and securing understanding of reflection

Lesson outcome

This lesson will be removed by end of Summer Term 2025.