This is a lesson I created for third graders about what lines of symmetry are and I included a few activities for them to do related to that.

2. Definition

A line that divides a figure into two
halves that are reflections of each other.

3. Find the line of symmetry in this
diamond.

4. Answer:

5. Find the line of symmetry on
this car.

6. Answer:

7. Find the lines of symmetry in
this hexagon.

8. Answer: Hexagons have many
lines of symmetry.

9. Find the line of symmetry in this
triangle:

10. Answer: This triangle has NO
lines of symmetry

11. Conclusion:
Shapes can have no lines of
symmetry, one line of symmetry, or
many lines of symmetry.