More than a centimeter long.

1 yuan coin 2.5 cm in diameter.

Four 1 yuan coins are placed side by side, which is 10 cm. The diameter of the pentagonal coin is 2 cm, and the five pentagonal coins placed side by side are also 10 cm.

10 cm is 10 1 cm. The nail width of human thumb is about 1 cm.

A centimeter is a unit of length measurement, equal to one hundredth of a meter. The unit of length, abbreviated as cm in English symbol.

1cm (cm) = 10mm (mm) =0. 1dm (decimeter) =0.0 1m (meter). Extended data 1, the length unit 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.

2. The unit of measurement is the scale that people choose to measure a measurable size, and its value is determined by the definition of the unit. The physical standard with the highest accuracy reflects the numerical value given by the unit definition, which is called the measurement benchmark of the unit.

Refer to cm- Baidu Encyclopedia.

How long is a centimeter?

As shown in the figure, the distance between two points AB on a straight line corresponds to one centimeter of the ruler, that is, one centimeter.

A straight line consists of countless points. A straight line is a part of a surface and then constitutes a body. There is no end point, it extends infinitely to both ends, and the length cannot be measured. A straight line is an axisymmetric figure.

It has countless axes of symmetry, one of which is itself, and all lines perpendicular to it (there are countless axes of symmetry). There is only one straight line between two non-overlapping points on the plane, that is, two non-overlapping points determine a straight line. On the sphere, countless similar straight lines can be made after two points.

The most basic element of geometry. In the axiomatic system of Euclidean geometry established by D Hilbert, points, lines and surfaces belong to basic concepts, which are defined by their relationships and five groups of axioms.

Line segment, a general term in technical drawing, refers to a continuous or discontinuous drawing line composed of one or more different line elements, such as a real line segment or a two-point long line segment composed of "long stroke, short interval, point, short interval, point and short interval". [ 1]

Connect two points with a ruler and you get a line segment. The length of a line segment is the distance between these two points.

The length of the line segment connecting two points is called the distance between these two points.

Line segments are represented by letters A and B or lowercase letters representing their two endpoints. Sometimes these letters also represent the length of the line segment, which is recorded as line segment AB or line segment BA, line segment A .. where A and B represent the two endpoints of the line segment.

How long is one centimeter on the ruler?

The length of one centimeter on the ruler is shown in the following figure:

About centimeter unit conversion:

1 cm = 10 mm = 10000 micron = 1000000 nanometer =0. 1 decimeter =0.0 1 meter = 0.0000/kloc-0. )

Commonly used units are millimeter (mm), centimeter (cm), decimeter (dm), kilometer (km), meter (m), micron (micron), nanometer (nm) and so on. Length units play an important role in various fields.

Extended data

Legend of the 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.