A geometrical reflection is one of the easiest types of geometrical transformation. The only thing that must be specified to specify the reflection is the mirror line. If we are dealing with Cartesian axes, we should name the mirror line correctly (e.g. y=2 or x=3).

To “do” a reflection, for every point on the object there must be a point at an equal distance on the other side of the mirror line in the image.

Example

Exercise

Let’s complete exercise 15C on pages 249 and 250 of the textbook:

The answers are below: