Transformations

Translation

Slides a shape by a vector $\binom{a}{b}$.

• $a$: horizontal movement (right +, left −)
• $b$: vertical movement (up +, down −)

Shape and size stay the same.

Reflection

Flips a shape over a mirror line.

• Common lines: $y = x$, $x$-axis ($y = 0$), $y$-axis ($x = 0$), $y = -x$.
• Each point is the same distance from the mirror line on the opposite side.

Rotation

Turns a shape around a centre point.

• Specify: angle, direction (clockwise/anticlockwise), and centre of rotation.

Enlargement

Changes the size using a scale factor from a centre of enlargement.

• Scale factor > 1: bigger.
• Scale factor between 0 and 1: smaller.
• Negative scale factor: inverted (other side of centre).

Always state the type and all required details:

• Translation: the vector.
• Reflection: the mirror line.
• Rotation: angle, direction, centre.
• Enlargement: scale factor, centre.