# Year 7

## Measurement and Geometry

### Transformations of the plane

Each of the triangles \(T^\prime\), \(T^{\prime\prime}\) and \(T^{\prime\prime\prime}\) are obtained from triangle \(T\) by moving it.

Triangle \(T^\prime\) is formed by rotating triangle \(T\) about the point \(C\).

Triangle \(T^{\prime\prime}\) is formed by reflecting triangle \(T\) in the \(y\)-axis.

Triangle \(T^{\prime\prime\prime}\) is formed by translating triangle \(T\) across and down.

When the triangle is moved in this way we call the movement a transformation. The three types of transformations considered in this resource package are translations, reflections and rotations.

#### Properties of these transformations

When a figure is translated, rotated or reflected:

- Line segments move to intervals of the same length
- Angles move to angles of the same size.