Symmetry

Our focus today was symmetry.  We began by working with an octagon.  We defined the term "axis of symmetry" as being a line though a shape so that each side is a mirror image.

We found that an octagon has a number of lines that could be an "axis of symmetry".  There is a vertical line of symmetry, a horizontal line of symmetry, and two diagonal lines of symmetry.  Therefore, an octagon has reflectional symmetry as well as rotational symmetry.  To view the lesson and note-taking, please see the video:  Lines of Symmetry.

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Reflectional Symmetry

Next, we moved into a more detailed lesson on reflectional symmetry.  We worked with a trapezoid, square, and parallelogram finding their lines on symmetry.

Rotational Symmetry

Then we moved into rotational symmetry.  Again, we used the trapezoid, square, and parallelogram, however, this time we rotated the shapes to help us determine whether they had rotational symmetry or not.  To view this part of the lesson, please watch the video:  Reflectional and Rotational Symmetry.

I found the idea for this lesson from an Interactive Math Journal from Runde's Room on teacherspayteachers.com.

To complete the lesson, I asked the kids to think about today's lesson using a 3-2-1.  Their prompt was:

• 3 new things I learned.
• 2 things I thought were interesting.
• 1 thing I need more information about.

HOMEWORK:  Countdown 5.5