Circle Area

Area x
Circumference x
Diameter x


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A circle is one of its kind among all the geometrical shapes; it is the only shape where all points are equidistant from a given point called the Center. Thus a circle is formally defined as:

A circle is a closed plane consisting of all points which are equidistant from a fixed point called as Center. Note that, a circle:

  • Looks like the letter ‘O’ which is round in shape.
  • Is a 2-D shape
  • Does not have any angles.
  • One key parameter that you need to know for performing any calculations on a circle is its ‘radius’.
  • The radius is the distance of each point on the circle from a point that is equidistant to all the points on it.

The radius of a circle is generally represented by the letter ‘r’.

A circle refers to only the outer boundary whereas a disc refers to the whole shape including the inside part.

Since the circle is curved and doesn’t contain any line segments surfaces, it doesn’t come under the family of the polygon

Features of CalculatorHut’s Circle Area Calculator

    With CalculatorHut’s circle area calculator, you can easily calculate the following parameters of a circle:

  • Area
  • Area refers to the space enclosed inside the boundary of a circle

    . A= π * r2, where r is the radius of the circle
  • Diameter
  • Diameter is a line segment whose endpoints lie on the circle and which passes through the center of the circle.

    A diameter is the largest distance between any two points on the circle.

    A diameter, represented by ‘D’, is equal to twice the radius of a circle.

  • Circumference
  • It is the total length of the circle, when you put cut it at a point, and put in the form of a straight line.

    The circumference is represented by ‘C’.

    C=2 * π * r, where r is the radius of the circle.

    It is easier to square the circle than to get around a mathematician. – Augustus de Morgan, Indian Mathematician

Key Concepts about Circle

  • A Chord is a line segment drawn in a circle with both its endpoints lying on the circle.
  • The diameter is the longest chord of a circle. When you extend a chord infinitely, it is called a secant.
  • The ratio between the circumference and the diameter is always, same no matter what size the circle may be.

Fascinating Facts About a Circle

  • The word circle is derived from the Greek word ‘Kirkus’, which means a ring and the Greeks believed that it is the symbol of infinity — a line that never ends.
  • A circle contains the highest level of symmetry amongst all geometrical shapes.
  • ‘π’ or pi is one of the mathematical constants is obtained when we divide a circle’s circumference by its diameter. The approximate value of π is 3.14159265358979 which makes it an irrational number.
  • There is a form of divination called Gyromancy, in which a person walks in circles until they fall over through dizziness. It is said that one can interpret the outcomes of the future events based on the position one falls.
  • In a research carried out in 2009 by Max Planck Institute for Biological Cybernetics in Tubingen, it is found that in situations where there are no navigation clues such as in a thick for or snowstorm, humans always end up moving in a circle.
  • From the main foraging party, if a group of army ants gets separated, they lose the track and begin to follow one another causing to form continuously rotating circles. Due to this, they get exhausted and die.
  • The encyclopedia is called as “circle of learning” and was initially used to indicate a well-rounded education.
  • The shape of the Parliament of India building is circular, which is based on the Ashoka Chakra. The Centre of the building is the known as Central Chamber.
  • A small fish named male puffer fish creates circular patterns on the sea floor. Scientists are still researching why it does this way.

How to use CalculatorHut’s Circle Area Calculator?

We know that the area a circle is ’π’ times the radius squared of the circle and the circumference is two times the product of ’π’ and ’r’ . All we need is to find the radius of the circle. Since π is an irrational value, it is challenging to calculate the area and circumference of the circle and is a time taking process. Even if there is a small calculation that goes wrong the entire value chance.

To avoid all this, it is better to go with this Circle Area Calculator as one we get accurate results in seconds. Even by adjusting the units of the circle you can perform in different units and get whatever result you need. This not only saves your time but also helps you to complete your task with greater accuracy.

Life is one circle. The end of one journey is the beginning of the next. – Joseph M Marshall

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