Before proceeding to know the meaning of the term concave, it is necessary to discover its etymological origin. In this case, we can state that it is a word that derives from Latin, exactly from “concavus”, which can be translated as “excavated round”. Word that is the result of the sum of two clearly differentiated parts:
-The prefix “with”, which means “together”.
-The adjective “cavus”, which is synonymous with “empty” or “hollow”.
According to DigoPaul, concave is an adjective that refers to that which has an inward curvature. It can be said that something concave is similar to the internal sector of a sphere or a circle.
A spoon, for example, is a utensil that has a handle and a concave surface. This concavity makes it useful to eat liquid, soft or very small food. If a person inserts a spoon into a soup plate, the broth will enter the concave sector and thus the subject will be able to drink it comfortably.
A concave mirror, on the other hand, has the reflective surface curved inward. In this way the light is reflected in such a way that it converges on a focal point. Depending on the distance between the mirror and the object, the reflected image takes on different shapes.
The concave mirrors, therefore, capture the light that falls on the reflective surface and deflects the rays towards a point. This class of mirrors is used to increase the size of images in devices such as telescopes, to cite one case.
In the field of geometry, a concave angle is defined as one that measures less than 360º and more than 180º. These angles can also be called incoming or reflections. As for concave polygons are figures having at least a concave inner angle and, moreover, when traversed by a straight line, are cut to the least three points.
In every concave polygon we can determine that there are several clearly differentiated parts such as these:
-The incoming angle, which is one that is greater than 180º.
-The outer point, which is the point that is not in what is the polygonal region.
-The interior, which is the set of all the interior points that the polygon in question has.
-The diagonal, which is the segment that is responsible for joining two vertices that are not consecutive.
-The polygonal region, which is the union of the polygon and its interior.
Within the scope of literature, this term has been used on a long list of occasions to give titles to different works. A good example of this is the book “Cóncava mujer”. It is a book of poems written by the Cordovan author Juana Castro.
It should be noted that the concave is complemented by the convex, a term that refers to an outward curvature.
Precisely the Mexican singer Alejandro Fernández has a song entitled “Concavo y convexo”. It was published in 2013, is part of his album “Confidences” and revolves around the difficulties of love.