Study Notes
Transformations involve changing the position and/or size of a shape, including translation, rotation, reflection, and dilation.
- Translation — moving a shape without rotating or flipping it. Example: Moving a triangle 3 units right and 2 units up.
- Rotation — turning a shape around a fixed point. Example: Rotating a triangle 90° clockwise around the origin.
- Reflection — flipping a shape over a line to create a mirror image. Example: Reflecting a triangle over the line x=2.
- Dilation — resizing a shape larger or smaller, while maintaining its proportions. Example: Enlarging a triangle by a scale factor of 2 from the origin.
Exam Tips
Key Definitions to Remember
- A transformation changes the position and/or size of a shape.
- A reflection is a mirror image of a shape across a line.
- A rotation involves turning a shape around a point.
- A translation moves a shape without rotating or flipping it.
- An enlargement changes the size of a shape with respect to a center.
Common Confusions
- Confusing rotation direction: clockwise vs. anticlockwise.
- Forgetting to specify the center of rotation or enlargement.
- Mixing up translation vectors with coordinates.
Typical Exam Questions
- Describe the transformation that maps triangle A onto triangle B? Reflection in the line y = x.
- What is the inverse of a rotation of 90° clockwise, center (2, 3)? A rotation of 90° anticlockwise, center (2, 3).
- How do you describe a translation by the vector (3, -2)? Move the shape 3 units right and 2 units down.
What Examiners Usually Test
- Ability to describe transformations using coordinates.
- Understanding of combined transformations.
- Correct use of vectors to describe translations.