How are diameters measuredin centimeters or inches?

Answer 1

In most countries, in centimetres.

Answer 2

Diameters are typically measured in either centimeters or inches by using a ruler or a caliper to measure the distance across the widest part of a circle or a round object. The measurement is taken from one side of the circle to the opposite side, passing through the center point. The result is then recorded as the diameter of the object in the chosen unit of measurement.