Symmetry

Lesson Plan - Get It!

Audio:

Take a sheet of paper and hold it horizontally.

Fold this paper in half (hamburger style).

• Did all the corners line up neatly?
• Did it fold perfectly?

If so, your paper has symmetry!

If you can fold an object in half and all the parts line up perfectly, the object has symmetry. For example, the butterfly below has symmetry. If you were to fold this butterfly in half, the wings, body, and antennae would line up perfectly:

Look at the objects below. All of these objects have lines of symmetry.

A line of symmetry is an imaginary center line where, if you folded it on that line and made that the crease, your object would be folded perfectly in half. Folding a symmetrical object along the line of symmetry would allow all of the edges to line up with each other.

Some objects have multiple lines of symmetry.

For example, look at the square below. The square has four lines of symmetry. If you were to fold on any of those lines, the square would fold perfectly in half.

Some objects only have one line of symmetry. The x shape below only has one line of symmetry.

• How many lines of symmetry does the blob under the square have?
• Can you find the line of symmetry on the last object?

^{Image by Dbc334, via Wikimedia Commons, was released into the public domain.}

Watch Intro to Symmetry: All About Symmetry for Kids - FreeSchool (FreeSchool, below) to learn more about symmetry. While watching the video, pay attention to which objects have symmetry and which objects do not have symmetry:

After watching the video, move on to the Got It? section to practice identifying symmetrical objects and lines of symmetry.