How_To_Be_Good_At_Math

260 GEOMETRY •^ REFLECTION

Lines of reflection

A shape and its reflected

image are always on

opposite sides of the

line of reflection. Every

point on the image is

the same distance

from the line of reflection

as the pre-image. The

line of reflection can be

horizontal, vertical,

or diagonal.

Reflection

In maths, we call a change in the size or position of an object

a transformation. Reflection is a kind of transformation in

which we make a mirror image of an object.

The original object is

called the pre-image.

The reflected version of

the original shape or

object is called the image.

In this reflection, the

long sides of the image

and pre-image are parallel

to the line of reflection.

What is reflection?

A reflection shows an object or

shape flipped so it becomes its mirror

image across a line of reflection.

This reflection is across

a diagonal line. The

sides of the shapes sit

along the line of reflection.

In this reflection, no

part of the shape is

parallel to or touching

the line of reflection.

Line of

reflection

The line of reflection

can be diagonal

Reflection means

flipping an object or

shape over an

imaginary line.

A reflection takes place over

a line of reflection, like this

one. It’s also called the axis of

reflection or mirror line.

260_261_Reflection.indd 260 29/02/2016 18:57