Hello, I’m Mr Firth, and together we’re going to learn about lines of symmetry. Symmetry is when one side of a shape looks exactly like the other—just flipped. Lots of buildings use symmetry because ...

To most people, “symmetry” means the bilateral symmetry exhibited by, say, a butterfly, or the human face. That is, if you take a picture of a butterfly and draw a straight line down the middle of the ...