# What is rotation of shapes?

We explain what the term rotation means in geometry, how primary-school children are taught to rotate shapes clockwise or anticlockwise or about the centre, and how to combine rotation with coordinates.

## What is rotation of shapes?

Rotating shapes means moving them around a fixed point (clockwise or anticlockwise, and by a certain number of degrees). The shape itself stays exactly the same, but its position in the space will change.

## How to rotate shapes

Children need to have a good knowledge of angles before they can carry out tasks involving rotating shapes. They need to know off-by-heart that 90˚ is a quarter turn, 180˚ degrees a half turn, 270˚ a three-quarter turn and 360˚ a full turn.

They may be given a shape like the following one in blue and asked to rotate it 90˚ clockwise about the vertex marked with the red dot:

They should end up with a new shape (in red; the original shape is still shown in blue) like this:

Alternatively, they may be given a shape and asked to rotate it about its centre. In this case, someone started with the pink shape and rotated it 180˚ anticlockwise about the vertex marked with the red cross, resulting in the green shape:

It is a good idea to give children cut-out shapes so that they can physically rotate the shapes to gain a better understanding of this concept. They then need to move onto being able to work out how to rotate the shapes without this support.

## Rotating shapes and coordinates

Questions on rotation can be combined with coordinates. For example, a child might be shown this shape:

They might be asked the following question:

If this shape is rotated 90˚ clockwise about point B, what will the co-ordinates of point A be on the newly rotated shape?

They would then need to rotate the shape (mentally or with the help of a small square) and see where point A would be on the rotated shape (5, 9).

Shapes can also be reflected In a mirror line and translated.