Who invented the ruler?

Rulers are the result of long-term accumulation by the ancients. As for the specific inventor, there is no clear record. ? One of Lu Ban's inventions is that he can draw a right triangle correctly, which is also called class ruler.

One of Lu Ban's inventions is that he can correctly draw a right triangle, also called a class ruler, and can tell craftsmen which sizes are irregular and which ones are unlucky according to the rules of divination (geomantic omen). These rulers were bought today.

Silk cloth ruler, also known as tailor ruler or cutting ruler, originated from the ruler with class ruler, but it has not been passed down from generation to generation, and has long lost its standard and become another ruler system.

Extended data:

Precautions for ruler:

1, first of all, use the ruler correctly. For example, it is best not to use a plastic ruler when delineating materials, which will easily scratch. There are also many people who will make a mistake, that is, they will draw lines quickly, and then they will draw along the ruler because of its slippery characteristics, which will blur the graphics, so the speed is moderate.

It's best not to mix a ruler with a knife or metal stationery. When mixing with pens, be sure to cover the pen cover.

3, be sure to prevent exposure and long-term sun exposure, especially the plastic ruler has poor temperature resistance and will be deformed.

4, it is best not to brush clean, which means try not to dirty the ruler.

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