| A. Triangles(三角形) everywhere B. Introduction C. History of triangles D. Cardboard today E. History of cardboard F. Why cardboard is strong |
Mark's science blog
How cardboard is like a bridge
Hello everyone! Today, I visited a museum and found out a lot of amazing information about cardboard!
In 1879, a Scottish engineer called Robert Gair invented the cardboard box. He could make a lot of cardboard boxes very quickly, and so for the first time, food companies could use cardboard to hold food. In 1906, the Kellogg company started using very thin cardboard boxes for its cereal. This was the first time that a box had the name and picture of the food on the outside!
Today, we use cardboard boxes for many different things because cardboard is so strong.
Do you know why cardboard is so strong? Inside each piece of cardboard here are a lot of triangle. Triangles are really strong: they can carry a lot. Do you sometimes make a house of cards? If you use triangles, it works. If you try it with square shapes, it doesn't work. Try it and see! The triangle shape is the strongest.
I learned that there are triangle shapes everywhere: in bridges, in houses, on bikes and even on kites! Look at these pictures. Can you find the triangles?
