Transformations — Year 8 Revision Notes
These notes cover the four transformations — reflection, rotation, translation and enlargement — and how to describe each one fully, at Year 8 (Stage 8) level.
Reflection and rotation
A reflection flips a shape across a mirror line, such as the x-axis, the y-axis or the line y = x; every point stays the same distance from the line. A rotation turns a shape about a centre through an angle (often 90° or 180°) in a given direction. Tracing paper is a useful check for both.
Key Facts & Formulas
- Reflection needs a mirror line
- Rotation needs angle + direction + centre
Tips
- For a reflection, each point is the same distance behind the mirror line.
- For a rotation, state the angle, direction and centre.
Translation
A translation slides a shape without turning or flipping it, described by a column vector. The top number gives the movement across and the bottom number the movement up or down. A column vector with top 3 and bottom −2 means 3 right and 2 down.
Key Facts & Formulas
- Column vector: top = across, bottom = up/down
- Top 3, bottom −2 = 3 right, 2 down
Tips
- The shape stays exactly the same size and way up.
- Top number across, bottom number up or down.
Enlargement
An enlargement changes the size of a shape by a scale factor from a centre of enlargement. A scale factor of 2 doubles every length, so the new shape is twice as big. Measure each distance from the centre and multiply it by the scale factor.
Key Facts & Formulas
- New length = scale factor × original length
- Scale factor 2 → lengths double
Tips
- Multiply distances from the centre of enlargement.
- State both the scale factor and the centre.
Revision Checklist
- I can reflect a shape in a mirror line
- I can rotate a shape about a point through 90° or 180°
- I can translate a shape using a column vector
- I can enlarge a shape by a whole-number scale factor and describe a transformation fully
Frequently Asked Questions
Does a shape change size when it is translated, reflected or rotated?
No. Translations, reflections and rotations all keep the shape exactly the same size and shape — only its position or orientation changes. Only an enlargement changes the size.
Build strong foundations in Transformations
A free trial class with Teacher Rig helps your Year 8 child master Transformations now — so IGCSE Maths feels familiar, not frightening, later.
Heading toward IGCSE? See how Transformations develops in IGCSE Transformations and Vectors (Cambridge 0580) →