Crown It is a concept with multiple uses. The ornament made with flowers and other materials that is located above the head and represents something symbolic; a round object, especially if it is in an elevated place; the grouping of leaves and flowers arranged in a circular manner; the currency of certain nations; the dental region that appears on the gum, and the artificial object that cares for or replaces this dental part is called a crown.
From Latin circularis, circular it's something linked to a circle . The concept is also used to name the procedure that seems to never end, since it ends in the same place where it begins, and to the instruction of an authority directed to its subordinates.
The notion of circular crown It is used in the field of geometry to refer to the flat figure that is determined by a pair of concentric circles . If you want to graph mentally, it is necessary to imagine a circle within a larger one; then, we visually subtract the space occupied by the smallest, obtaining a circular strip with the "hollow" center, and that is precisely the circular crown of the two figures.
To understand this definition, we must first be clear about the notion of circumference : is a closed, curved and flat line, with equidistant points from the fixed and coplanar point called center ; the distance between any of the points and the center is known as the radius and the segment formed by two aligned radii, on the other hand, is called diameter .
The area of a circular crown is obtained by prior calculation of the surface of each of the circles; To do this, we will first determine the radio r, belonging to the small figure, and the R, of the big one. Having identified both areas, we subtract the square of the smallest multiplied by pi, squared of the largest multiplied by pi: pi x R x R - pi x r x r, which is equivalent to pi x (R x R - r x r), if we take out the common factor.
A concept associated with the circular crown is that of circular trapezoid, which is just a trapeze whose bases have a curvature. Again, it is very useful to try to mentally graph the term to internalize it and understand it completely; thinking of a circular crown, if we "cut" a portion, as if it were a cake, we would obtain a figure similar to a rectangle, but crooked. To find its area, it will also be necessary to calculate the surfaces of the concentric circles in question, with which we will find the area of the circular crown.
Once we have that value, it is necessary to understand that it is the surface of a 360 degree circular crown, that is, it represents the area of the closed figure. However, since in this case we are interested in finding out the surface of a portion of said crown, the angle will be clearly smaller. With this data in hand, which for the example we can represent with 56 degrees, the last part of this calculation is very simple, since it is a simple rule of three simple: if the area corresponds to 360 degrees to, for 56 degrees your area will be 56 x a / 360, which will give us a result in the unit of measure that we have chosen, which may well be centimeters, always squared.
The circular crown is a relatively difficult geometric figure to represent graphically, but extremely common in everyday life, as it is found in infinity of logos and symbols, such as signs used to prohibit the parking of vehicles in certain areas or signs that indicate the maximum speed of a highway.