Fun with Symmetry
Mirrors and squares
Use a mirror to see shapes made of squares change.
In your book, Maths Mela (Chapter 11), shape A is a strip of 2 squares side by side. A mirror stands upright on the paper. You see the part of the strip in front of the mirror, and its reflection. The part behind the mirror is hidden. By moving the mirror, you can see new shapes!
Put the mirror at the end of the strip. You see both squares and their reflection: 4 squares in a row. Put the mirror on the line between the two squares. You see one square and its reflection: 2 squares.
Put the mirror across the middle of the second square. In front of it are the first square and half of the second. With the reflection, that makes 3 squares in a row. Put the mirror across the middle of the first square, with only the half square at the end in front of it. With its reflection, you see just 1 square.
Put the mirror along the long edge of the strip. The 2 squares and their reflection make a 2 × 2 block of 4 squares. And for an L shape of 3 squares, put the mirror slanting across the second square, from one corner to the opposite corner. The first square is reflected to sit next to the second square, making an L.
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