Crush Classroom Boredom by running an escape room at school. Just download, print & play! Show me...

# Teaching 4.G.A.3 – Recognize and Draw Lines of Symmetry & Identify Line-Symmetric Figures

## Geometry – 4th Grade

#### Draw and identify lines and angles, and classify shapes by properties of their lines and angles.

CCSS.Math.Content.4.G.A.3
Recognize a line of symmetry for a two-dimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify line-symmetric figures and draw lines of symmetry.

Teacher Notes
A line of symmetry divides a shape into two congruent parts. A figure can have one line of symmetry, more than one line of symmetry or none at all.

Student Knowledge Goals
I know a figure is symmetric when it can be divided by at least one line into two congruent parts where the two parts are mirror images of one another.
I know a line of symmetry is a line on which a figure can be folded so the two parts match exactly.
I know a figure can have more than one line of symmetry.
I know a figure with at least one line of symmetry is symmetric.
I can identify shapes that are symmetric.
I can categorize two-dimensional figures as line-symmetric and non-line-symmetric.
I can draw in the line(s) of symmetry for line-symmetric shapes.
I can explain why a given shape is non-line-symmetric.

Vocabulary
line of symmetry
symmetry

Lessons
Engage NY Module 4 D-12 – Recognize lines of symmetry for given two-dimensional figures; identify line-symmetric figures and draw lines of symmetry.
Engage NY Module 4 D-14 – Define and construct triangles from given criteria.  Explore symmetry in triangles. *Related but not CCSS required
Symmetry
Lines of Symmetry

Student Video Lessons
Learn Zillion – Recognize and draw lines of symmetry and line-symmetric figures
Study Jams – Line of Symmetry

Online Problems and Assessments
Khan Academy – Questions and Video Lessons
Lines of symmetry

Online Games
Symmetry