The unit of length refers to the basic unit for measuring spatial distance, which is formulated by human beings to standardize the length. Its international unit is "meter" (symbol "m"), and commonly used units are millimeter (mm), centimeter (cm), decimeter (dm), kilometer (km), meter (m), micron (μm), nanometer (nm) and so on. Length units play an important role in various fields.
When measuring the length of a line segment, it is necessary to select a line segment as the measurement standard and specify its length as 1, which is called the length unit. There are many units of length, the main unit is meter, and the rest are derived units. When measuring, choose the appropriate length unit according to the actual needs. For example, the length of runway is measured in meters, the distance between two cities is measured in kilometers, and the distance of long jump is measured in centimeters, and so on.
International length measurement units are micron, millimeter, centimeter, decimeter and meter. The conversion relationships between units are 1 m = 1 decimeter, 1 decimeter = 1 0cm,1cm =10mm,1mm =/kloc-0.
The traditional units of length in China are zhangs, feet, inches, centimetres and minutes. The conversion relationships between companies are 1 ft = 1 ft, 1 ft = 1 in,1in =1min =1min. Converted into international length measurement units: 1 cm ≈3.33 m, 1 ft ≈3.33 decimeter, 1 inch ≈3.33 cm.