Key Terms
- Isometry – a rigid transformation of a geometric figure on a coordinate plane that preserves congruency (size & shape).
- Pre-Image – a geometric figure before a transformation; the original figure.
- Vertices are labeled with capital letters, such as Δ ABC
- Image – a the figure after transformation; the new figure.
- Vertices are labeled with the same capital letters as the pre-image, however, they also include a prime (apostrophe: ‘ ) symbol after each letter: Δ A’B’C’
- Translation – sliding a figure up, down, left, or right on a coordinate plane.
- Reflection – flipping a figure over another geometric figure, usually a point or a line, on a coordinate plane.
- Rotation – spinning a figure around (about) a fixed point on a coordinate plane.
Lesson Links
- Math Bits – Notes with visuals
Videos
Video # 1 – Translations
Video # 2 – Reflections