# Reflectional Symmetry

- Author:
- Brooke Becker

- Topic:
- Symmetry

The butterfly below has

**reflectional symmetry**. The**line of symmetry**is the vertical line through the center of the butterfly, splitting it into two halves that are mirror images of one another. Use the construction to answer the following questions: 1) Move point B that lies on the line of symmetry. What do you notice about the distance of A and A' from the line of symmetry, regardless of where B is? 2) Move point A (you will see that it will leave a red, dotted path) to parts of the butterfly you think appear to be symmetric. How does each movement effect A'? 3) If you did not move point A across the line of symmetry, do so now. How does this effect A'?After exploring the line of symmetry and implications for reflections, answer the following:
1) If you were to plot a segment with coordinates A(-2,3) and B(-2,7), what would segment A'B' if it was a reflection over the y-axis (the y-axis is the line of symmetry)?
2) If you were to draw a perpendicular line from point A to the y-axis, what is the distance A is from the y-axis? Without drawing A', what is the perpendicular distance A' is from the y-axis?