12.3 Transforming Shapes

You can use a combination of reflections, translations and rotations to transform a shape. You can also describe the transformation that maps an object onto its image.

To describe a reflection you must give: 

• the equation of the mirror line

To describe a translation you must give: 

• the column vector

To describe a rotation you must give: 

• the centre of rotation
•  the number of degrees of rotation (or fraction of whole turn)
• the direction of the reaction (clockwise or anticlockwise)