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 (micron) and nanometer (nm). Length units play an important role in various fields.
Area unit refers to the unit for measuring the surface size of an object. The order from small to large is: mm? (square millimeters), centimeters? (square centimeter), dm? (square decimeter), m? (square meters), huh? (hectares), kilometers? (square kilometers). In the International System of Units (SI), the standard unit area is square meters (m2), and the area is a square area one meter long.
Extended data:
I. Conversion of length units
1 decimeter = 0.000 1 kilometer (km) = 0. 1 meter (m) = 10 centimeter (cm) = 100 millimeter (mm).
1 cm =10mm = 0. 1 decimeter = 0.0 1 m = 0.0000 1 km.
Second, the public area unit
Square kilometers, square meters, square decimeters, square centimeters, square millimeters.
A square with a side length of 1mm and an area of 1mm2.
A square with a side length of 1 cm and an area of1cm 2.
A square with a side length of 1 decimeter and an area of 1 square decimeter.
A square with a side length of 1 m and an area of 1 m2.
A square with a side length of 1 km and an area of 1 km2.
Baidu Encyclopedia-Area Unit
Baidu encyclopedia-length unit