Geometry · Transformations
Reflection
HSG-CO.A.5
Definition
A transformation that flips a figure over a line, creating a mirror image.
Teach it
Where it is taught, with guided notes, practice, homework, an exit ticket and an interactive Teacher Deck.
Examples
- Reflecting triangle ABC over a line produces triangle A'B'C', a mirror image.
- Flipping a figure over the y-axis reverses its left-right orientation.
Key rule
A reflection always flips a figure over a line, reversing its orientation.
Memory hook
Flip it over the line — mirror image.