What is symmetry? Some grade three and four students will help show you what symmetry is, using the paper airplanes they made. Here is a diagram of a well-designed airplane. You can see the actual paper plane on the right. The yellow line we've added in the centre of each plane illustrates that each plane can be split into two halves that are identical in size and shape. They are also mirror images of each other ... which means that each half points in the opposite direction. The yellow lines of symmetry divide each plane into two equal parts. Symmetry is important when designing a paper airplane, because the two wings have to be identical. If they aren't, the plane won't fly straight. Both planes have left and right wings which are mirror images of each other. They are symmetric. Each plane has symmetry. Many other things have symmetry too. Have a look at the pictures below to see some things that are symmetric. Man-made things have symmetry, and so do many things in nature. You can also draw designs which are symmetric. Here is a design which is symmetric two ways ... up & down, and left & right. Designs which have symmetry are often pleasing to look at, so they are used on wallpaper, on rugs, and in paintings. After making the airplanes, they had to be tested, of course! Main Page