Plane Transformations on a Coordinate Grid
Learn translation, rotation, reflection, and enlargement in MYP Maths Year 5. Covers coordinate grid transformations, full descriptions, and MYP task guidance.
What This Topic Covers
Plane transformations in MYP Year 5 Standard covers four types of transformation applied to shapes on a coordinate grid: translation, rotation, reflection, and enlargement. Students must be able to perform each transformation accurately, describe transformations fully, and recognise which properties are preserved.
The Four Transformations
Translation
Every point moves by the same vector (a, b). The shape is unchanged in size and orientation. Students must describe a translation using a column vector.
Rotation
The shape turns about a centre point by a given angle and direction (clockwise or anticlockwise). A full description requires the centre of rotation, the angle, and the direction.
Reflection
The shape is flipped across a mirror line. The mirror line must be stated precisely (e.g., y = x, x = 2). Each point is equidistant from the mirror line as its image.
Enlargement
The shape is scaled by a scale factor from a centre of enlargement. A negative scale factor produces an image on the opposite side of the centre. Fractional scale factors produce a smaller image.
What Is Preserved?
Translation, rotation, and reflection are isometries — they preserve size and shape. Enlargement preserves shape (angles) but changes size. Understanding this distinction matters for Criterion C communication tasks.
Common Mistakes
- Describing a rotation without stating direction or centre
- Using the wrong sign when applying a negative scale factor enlargement
- Reflecting across the wrong axis or misidentifying the mirror line equation
- Giving scale factor without the centre for enlargement descriptions
MYP Question Style
Tasks may ask students to perform a transformation, describe the transformation that maps one shape onto another, or find an invariant point under a given transformation. Combined transformation questions (apply A then B) are also common at higher demand levels.
Practice Approach
Use squared or coordinate paper to practise each transformation type. For descriptions, train yourself to check whether you have included every required element. Then move to combined transformations and practise identifying the single equivalent transformation.