This key facts covers Scale Factor Effects within Transformations: Enlargements for GCSE Mathematics. Revise Transformations: Enlargements in Geometry & Measures for GCSE Mathematics with 15 exam-style questions and 5 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 2 of 7 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Scale Factor Effects
| Scale Factor | Effect on Shape | Example |
|---|---|---|
| SF > 1 | Shape gets BIGGER | SF = 3: all lengths × 3 |
| SF = 1 | No change (same size) | SF = 1: shape unchanged |
| 0 < SF < 1 | Shape gets SMALLER | SF = 0.5: all lengths × 0.5 |
| SF < 0 | Enlarges AND inverts (opposite side) | SF = -2: twice as big, flipped |
Practice questions for Transformations: Enlargements
Which of the following statements correctly describes an enlargement?
Triangle P has vertices at (2, 1), (6, 1) and (2, 5). Triangle Q has vertices at (4, 2), (12, 2) and (4, 10). Describe fully the single transformation that maps triangle P onto triangle Q.
Quick recall flashcards
Scale Factor < 1
Shape gets SMALLER. SF = 0.5 means all lengths halved. Still called "enlargement" even though it shrinks!
Scale Factor > 1
Shape gets BIGGER. SF = 2 means all lengths doubled. Only transformation that changes size!