Geometry & MeasuresKey Facts
Common Mirror Lines
Part of Transformations: Reflections — GCSE Mathematics
This key facts covers Common Mirror Lines within Transformations: Reflections for GCSE Mathematics. Revise Transformations: Reflections in Geometry & Measures for GCSE Mathematics with 13 exam-style questions and 5 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 2 of 5 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 2 of 5
Practice
13 questions
Recall
5 flashcards
Common Mirror Lines
| Mirror Line | What Happens | Example |
|---|---|---|
| x-axis (y = 0) | y changes sign, x stays same | (3,4) → (3,-4) |
| y-axis (x = 0) | x changes sign, y stays same | (3,4) → (-3,4) |
| y = x | x and y swap | (3,4) → (4,3) |
| y = -x | x and y swap, both change sign | (3,4) → (-4,-3) |
| x = a (vertical) | Reflect horizontally in vertical line | (1,3) in x=3 → (5,3) |
| y = b (horizontal) | Reflect vertically in horizontal line | (2,1) in y=3 → (2,5) |