26.6666667 cm and 40 cm.

8 inch is 26.6666667 cm. (3 city inches = 10 cm, 3 inches = 7.62 cm)

1 meter = 3 feet = 30 inches = 100 cm.

So 8 inches = 26.666666667 centimeters.

If it's 3 inches = 3 x 2.54 cm = 7.62 cm.

Expanded:

The conversion between inches and centimeters is: 1 inch = 3 parts of 10 centimeters and 3 inches = 10 centimeters.

Centimeter English symbol that abbreviation is: cm., 1 cm = 1/100 m. 1cm (centimeter) = 10mm (millimeter) = 0.1dm (decimeter) = 0.01m (meter).

The text of their definitions was revised by the International Conference on Weights and Measures (CGPM).As of May 20, 2019, the definition of the meter was updated to read: a fixed value of 299792458 was chosen to define the meter when the speed of light in vacuum, c, is expressed in m/s. Where the second is defined by the frequency of cesium ΔνCs.On May 20, 1875 by the French government,

convened a meeting of representatives of the governments of 20 countries, formally signed the metric convention, recognized the metric system as the international common unit of measurement. At the same time, it was decided to establish the International Committee of Weights and Measures and the International Bureau of Weights and Measures. By October 1985, there were 47 member countries of the Metric System Convention.

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