https://www.ecalculator.co/calc/circle-area-calculator
While circles symbolically represent many different things for many different groups of people, including concepts such as eternity, eternity, and the whole, a circle by definition is a simple closed form. This is a set of all points in the plane that are the same distance from the point called the center. This can also be defined as a curve that is tracked by a point where the distance from the point remains constant as the point moves. The distance between each point in the circle and the center of the circle is called the radius, while the diameter of the circle is defined as the greatest distance between two points in a circle. In fact, the diameter is twice the radius because the largest distance between two points in a circle must be a linear segment through the center of the circle. Circle circles can be defined as the distance around a circle or as the length of a chain along a circle. All these values are connected by the mathematical constant π or pi, which is the ratio of the circumference of a circle to its diameter, which is about 3.14159. π is an irrational number, which means it cannot be stated exactly as a fraction (although it is often close to 22/7) and the decimal representation is never complete or has a constant repetition pattern. This is also a transcendental number, which means that the number is not the root of a non-zero polynomial that has a rational coefficient. Interestingly, Ferdinand von Lindemann's evidence in 1880 that it was transcendent finally ended the search for the millennium that began with an old geometer to sort the circle. This includes trying to build a square with the same area as a circle in a limited number of steps, only with a compass and standing. Although this is known today as the impossible and eager effort of a swollen old geometer to try to achieve a silly image by candlelight, it is important to remember that thanks to such people, so many mathematical concepts are definitely good today.
https://en.wikipedia.org/wiki/Area_of_a_circle
circle formula
D = 2R
C = 2πR
A = πR2
Where:
R: radius
D: diameter
F: tire
A: District
π: 3.14159