Activities With Symmetry in Snowflakes

Finding Lines of Symmetry

Make an accurate design of a snowflake on the board. Explain the concept of reflection symmetry to students, telling them that an object is symmetrical if it has two identical halves on opposite sides of a line passing straight through the middle of the object. Ask students to copy the snowflake design in their notebooks and try to identify its lines of reflection symmetry. Give students the hint that an object can have more than one line of symmetry.

Draw a snowflake on the board and ask students to copy the snowflake as big as their notebook sheet allows, without losing its proportions. Ask students to cut out the snowflake and fold it on a line of symmetry. This activity can help students visualize the concept of the symmetry axis, as the line where folding the shape results into two halves fitting exactly over another.

Have students unfold their paper snowflakes. Give one pushpin to each student and instruct them to place the snowflake on an open notebook and press the pushpin at its center. Ask students to mark one tip of the snowflake red and draw a short line next to it on the notebook's page. Then, have them trace the snowflake onto the page using a pencil. Tell students to rotate the snowflake until another tip, not from the red one, points towards the line and trace the snowflake onto the page again. Students can see that when the object is rotated to another point, it produces exactly the same trace, demonstrating the concept of rotational symmetry.

Students divide their notebook page into four parts by drawing a horizontal and vertical line that cross in the middle of the page. They then draw a simple three-line snowflake -- a vertical line cutting through an X -- on the bottom left part of the page, using a different color for each line. Starting from each of the snowflake's six tips, students shall draw straight lines that have the same color with their respective tip, cross through the page's middle and have the same length before and after the point. Connecting the ends of same-colored lines creates a snowflake identical with the one on the page's bottom. Explain that the two snowflakes are symmetrical in respect to the middle point of the page.