A circle is defined as a shape with all points at equidistant from a point at the center. The circle below is called as a circle A, because the center lies at point A. When you calculate the distance around a circle divided by the distance across a circle through its center, you will come close to a specific value based on the precision of your measuring technique. The value is approximately 3.1415926535897… and we use a Greek letter π (pronounced as Pi) to describe this number. The value π is a non-terminating value.
What Is Circumference Of A Circle?
What is meant by circumference of a circle? It is the one-dimensional linear measurement of the boundary across any two-dimensional circular surface. It follows the same principle behind finding the perimeter of any polygon which is why calculating the circumference of a circle is the same as finding its perimeter.
Since it is a curved surface, we can’t physically measure the length of a circle using a scale or ruler. But this can be done for polygons like squares, triangles and rectangles. Instead, we can measure the circumference of a circle using a thread. Trace the path of the circle using the thread and mark the points on the thread. This length can be measured using a normal ruler and you have the circumference of the circle.
An accurate way of knowing the circumference of a circle is to calculate it. For this, the radius of the circle has to be known. The radius of a circle is the distance from the centre of the circle and any point on the circle itself. The figure below shows a circle with radius R and center O. The diameter is twice the radius of the circle.The perimeter of a circle = 2πR
R is the radius of the circle
π is the mathematical constant with an approximate (upto two decimal points) value of 3.14
Pi (π) is a special mathematical constant, it is the ratio of circumference to diameter of any circle.
C is the circumference of the circle
D is the diameter of the circle
Apply the above information to solve the question given below.
Question: What is the circumference of the circle with diameter 4 cm?
Since the diameter is known to us, we can calculate the radius of the circle,
Therefore, Circumference of the Circle = 2 x 3.14 x 2 = 12.56 cm
The distance surrounding a circle is known as the circumference of circle. The diameter is the distance across a circle through the center. Π shows the ratio of the circumference of a circle to the diameter. Therefore, when you divide the circumference by the diameter for any circle, you obtain a value close enough to π. This relationship can be explained by the formula mentioned below.
C/d = π
Where, C indicates circumference and d indicates diameter. A different way to put up this formula is C = π x d. This formula is mostly used when the diameter is mentioned and the circumference needs to be calculated.
To learn all concepts in Math by applying them, log onto www.byjus.com.To watch interesting videos on the topic, download Byju’s – The Learning App from Google Play Store.
Practise This Question