The term diameter that concerns us now we can establish that it has its etymological origin in Greek, since it is the result of the union of several components of said language:

-The prefix “dia-”, which means “through”.

-The noun “metron”, which can be translated as “measure”.

This is the name given to the straight line that, passing through the center, joins two points on a sphere, a closed curve or a circumference. The largest width of a circular body is also called diameter. See Abbreviation Finder for acronyms related to diameter.

For example: *“Alarm among astronomers: an asteroid 800 meters in diameter will pass very close to our planet”*, *“The drain will be made with a pipe two meters in diameter”*, *“A stone two meters in diameter rolled down the mountain and crushed a vehicle*.

The Greek mathematician Euclid postulated, some three centuries before Christ, that the diameter of a circle is any segment that passes through the center of the figure and ends, in both directions, at its circumference. That same segment, on the other hand, establishes the division of the circle into identical parts.

The relationship between the diameter and the length of a circumference is a constant known as the pi number. It is an irrational number that is usually cut off at the first digits, taking it as 3.14.

Knowing the diameter of objects is important on many occasions. The diameter of a ring, for example, will determine whether or not this item can be placed on a finger. If the diameter is very wide, the ring will be large; on the other hand, if the diameter is very small, the ring will not fit. On the other hand, the diameter of a bottle will depend on whether it can be stored in a certain space in the refrigerator or in which part of a backpack it can be moved.

Undoubtedly, one of the most interesting diameters is that of the Earth. So much so that, throughout history, there have been numerous scientists who have worked to discover it. Thus, for example, we can establish that the first to try to discover this diameter was the Greek astronomer and geographer Eratosthenes of Cyrene (276 BC – 194 BC), who used a rudimentary method to make this measurement.

Specifically, that one was based on shadows and the summer solstice, among other aspects, which led him to conclude that the circumference of our planet was about 40,000 kilometers and the diameter was about 12,800 kilometers.

At present, we can establish that it has been established that the diameter of the Earth is about 12,756.247 kilometers, which makes it clear that the Greek astronomer cited, despite not having the technology or the knowledge that we have today, made a very rough calculation.

When speaking of diameter, we cannot fail to mention another term: radius. This we can establish that it is half the diameter and becomes the segment that joins the center of the circumference with any point on it.