LINE SYMMETRY & REFLECTIONS

REFLECTION SYMMETRY

Have you ever made a simple heart shape by folding and cutting paper?

The heart is made by using reflection symmetry.

Reflection symmetry is the SAME thing as line symmetry.

If you place a mirror on the line of symmetry, you will see half of the figure reflected in the mirror.

DO YOU NOTICE LINE SYMMETRY IN NATURE?

DO YOU NOTICELINE SYMMETRY IN NATURE?

DETERMINE IF THE OBJECT HAS LINE SYMMETRY. IF SO, DRAW ALL OF THE

LINES OF SYMMETRY.

3 Lines of Symmetry

DETERMINE IF THE OBJECT HAS LINE SYMMETRY. IF SO, DRAW ALL OF THE

LINES OF SYMMETRY.

4 lines of symmetry

DETERMINE IF THE OBJECT HAS LINE SYMMETRY. IF SO, DRAW ALL OF THE

LINES OF SYMMETRY.

No lines of symmetry.

How do we draw a reflection of this image?

What rules do we use to judge that we did it correctly?1. Same size, same shape

(congruent)2. Each point is the same

distance from the line of reflection.

3. If you draw a line from point A to the new point A (written as A’), it would be perpendicular to the line of reflection.

LINE REFLECTION

The new image has the same letters but with an apostrophe after them.

We read A’ as “A prime”

We read B’ as “B prime”

We read C’ as “C prime”

LINE REFLECTION

Drawing the reflection image of a figure is one kind of transformation.

A transformation is a geometric operation that acts on the original figure and produces a copy of the figure in a new position.

We call the copy the image of the original figure.

TRANSFORMATIONS

TELL WHETHER THE FOLLOWING IS A REFLECTION. IF IT IS NOT, TELL

WHY.

TELL WHETHER THE FOLLOWING IS A REFLECTION. IF IT IS NOT, TELL

WHY.

TELL WHETHER THE FOLLOWING IS A REFLECTION. IF IT IS NOT, TELL

WHY.

TELL WHETHER THE FOLLOWING IS A REFLECTION. IF IT IS NOT, TELL

WHY.

TELL WHETHER THE FOLLOWING IS A REFLECTION. IF IT IS NOT, TELL

WHY.

TELL WHETHER THE FOLLOWING IS A REFLECTION. IF IT IS NOT, TELL

WHY.

TELL WHETHER THE FOLLOWING IS A REFLECTION. IF IT IS NOT, TELL

WHY.

TELL WHETHER THE FOLLOWING IS A REFLECTION. IF IT IS NOT, TELL

WHY.

TIME TO PRACTICE DRAWING REFLECTIONS