How to Calculate the Circumference and Area of a Circle?

    A geometric shape that consists of all points in a plane that is at a specific distance from a particular point is known as a circle. This given point is called the center. We can also say that a circle is a simple closed curve that divides a plane into an interior and exterior region. There are many terms such as radius, diameter, the circumference of a circle, etc., that children need to learn about before they can claim to be masters of the topic. In this article, we will learn more about the various terms and concepts associated with circles.


    Circumference and Area of a Circle

    Terms of a Circle

    • Arc – An arc is a connected curve that forms a part of the circle.
    • Center – The point that lies inside a circle and is equidistant from all points that lie on the circle.
    • Chord – It is a line segment, the endpoints of which lie on the circumference of the circle.
    • Diameter – This is the longest chord of the circle. The endpoints lie on the circumference such that it passes through the center of the circle.
    • Radius – It is a line segment whose one endpoint is the center of the circle, and the other lies on the circumference. We can also say it joins the center to any point on the curve.¬†
    • Sector – When we have a region that is bound by two radii and either of the two arcs, it is called a sector.
    • Segment – When a chord and an arc together form a region, this part is called the segment of that circle. A segment does not contain the center of a circle.
    • Tangent – If a line touches the circle at exactly one single point it is known as the tangent.

    Circumference of the Circle

    The circumference of a circle is defined as the entire boundary of the circle. It can also be called the distance around the circle. We can find the circumference of the circle by the formula given below.

    Circumference = 2 * pi * r

    where r is the radius of the circle and pi = 3.14 or 22/7.

    As 2 * r is also equal to the diameter (d) hence, the circumference can be expressed in terms of the diameter as follows:

    Circumference of a circle = pi * d.

    Area of a Circle

    The area of circle can be defined as the region that is enclosed by the boundary of the circle. The formula to find the area of the circle is given below:

    Area of a circle = pi * r2 = pi * (d / 2)2

    Properties of Circle

    • If a radius is drawn perpendicular to a chord, then it bisects that chord and divides it into two equal halves.
    • Similar Circles have different radii¬†
    • If two tangents are drawn at the endpoints of a circle, they will be parallel to each other.
    • When the length of any chord of a circle increases, the perpendicular distance of that chord from the center of the circle decreases.


    Circles can prove to be a complicated topic as there are many different problems associated with them. The best way to deal with this issue is by attending a coaching institution such as Cuemath. Cuemath is an excellent online educational platform that helps children strengthen their mathematical concepts. The math experts take the help of resources such as math puzzles, games, apps, and interactive visual simulations to teach kids a topic. Thus, a child has an ironclad mathematical foundation.