Transformations · Grade 10
In Grade 10 you learn: negative and fractional scale factors.
A transformation moves a shape. Reflections, rotations and translations keep the size and shape the same (the image is congruent); an enlargement changes the size by a scale factor but keeps the shape (the image is similar).
Key facts
- Enlargement: give the scale factor and centre; every length is multiplied by the scale factor.
- Areas scale by the scale factor squared.
Worked examples
Example 1
Describe the single transformation that maps triangle A onto triangle B.
Answer: A reflection in the y-axis (the line x = 0)
Example 2
Enlarge P(3, 2) by scale factor 2 with centre (1, 1).
Answer: (5, 3)