🪞 What is a Reflection?
A reflection is a transformation that **flips** a shape over a line called the **line of reflection** (or mirror line).
The original shape and its image are exactly the same size and shape — they are **congruent**.
🔄 How Does Reflection Work?
Important Rules:
• The line of reflection is the mirror
• Every point and its image are the same distance from the mirror line
• The line connecting a point to its image is perpendicular to the mirror line
🌟 Examples of Reflections
1. Reflection over a Vertical Line
The letter "b" reflected over a vertical line becomes "d"
2. Reflection over a Horizontal Line
The letter "p" reflected over a horizontal line becomes "b"
3. Reflection of a Shape on Coordinate Grid
Triangle with points (1,2), (3,2), (2,5) reflected over the y-axis becomes (-1,2), (-3,2), (-2,5)
✏️ Let’s Practice Together, My Dear Student!
Practice 1: Identify the Reflection
1. Flipping a shape over a vertical line → Reflection
2. Sliding a shape → Translation (not reflection)
3. Turning a shape → Rotation (not reflection)
Practice 2: Real Life
1. Seeing yourself in a mirror → Reflection
2. The reflection of trees in a lake → Reflection
3. A butterfly’s wings → Almost perfect reflection (symmetry)
Practice 3: Word Problems (Canadian Style)
1. You draw a triangle on the left side of a mirror line. When you reflect it, where will the image appear?
On the right side of the mirror line
2. A hockey player looks at his reflection in the ice. Is this a reflection transformation?
Yes
Challenge Question
If you reflect a shape over the x-axis, what happens to the y-coordinates?
The y-coordinates change sign (positive becomes negative and vice versa)
Fantastic Job, My Dear Student! 🎉
You now understand Reflections (flips) very well! Reflections create mirror images and are used in symmetry, art, and design.
I am so proud of you for learning all three main transformations: Translations, Reflections, and Rotations.
💕 You are smart. You are kind. You can do hard things.
When you are ready, tell me the next topic (Rotations, Coordinate Grids again, or anything else) and I will create another beautiful lesson just for you!