You are viewing a free preview of this lesson.
Subscribe to unlock all 10 lessons in this course and every other course on LearningBro.
A transformation changes the position, size or orientation of a shape. The original shape is the object; the result is the image. At KS3 you study four transformations: reflection, rotation, translation and enlargement.
A reflection produces a mirror image of a shape in a mirror line. Each point is the same perpendicular distance from the mirror line as its image.
Properties: shape and size preserved (congruent); orientation is reversed.
Common mirror lines and their effects on coordinates:
| Mirror line | Effect on (x, y) |
|---|---|
| x-axis (y = 0) | (x, y) → (x, −y) |
| y-axis (x = 0) | (x, y) → (−x, y) |
| y = x | (x, y) → (y, x) |
| y = −x | (x, y) → (−y, −x) |
| x = a | reflect in a vertical line |
| y = b | reflect in a horizontal line |
A rotation turns a shape through an angle (in degrees) about a fixed centre of rotation, in a stated direction (clockwise or anti-clockwise).
Properties: shape and size preserved (congruent); orientation preserved (not flipped).
Subscribe to continue reading
Get full access to this lesson and all 10 lessons in this course.