Question

What’s the formula for circumference of a circle?

Answer 1

Hint: Here in this question, we have to explain what's the formula for circumference or it’s known as the perimeter of a circle. Here we have to explain the formula that is used to measure the length of the boundary of the circle using circle radius or diameter. It will explain briefly in the section below step by step.

Complete step by step solution:
The circumference of any shape defines the path or the boundary that surrounds the shape. In other words, the circumference is also called the perimeter, which helps to identify the length of the outline of any shape. Here we have to discuss the “Circumference of a circle”.
A circle is a round shaped figure that has no corners or edges. It is made up of many points arranged equidistant from a single central point and the point is known as the centre of the circle.

Circumference of the circle or perimeter of the circle is the measurement of the boundary of the circle. Whereas the area of the circle defines the region occupied by it. If we open a circle and make a straight line out of it, then its length is the circumference. It is usually measured in units, such as cm or unit m.

When we use the formula to calculate the circumference of the circle, then the radius of the circle is taken into account. Hence, we need to know the value of the radius or the diameter to evaluate the perimeter of the circle.

A radius is a measurement of distance from the centre of any point in a circular object to its outermost edge or boundary. The radius is constant value for each circle; it doesn't change.
The diameter of the circle is the maximum distance between any two points on the circumference. It’s twice the radius.
The formula of circumference of a Circle is:
The Circumference (or) perimeter of a circle \[ = 2\pi r\]
Or
 \[C = 2\pi r\]
Where,
 \[C\] is the circumference of a circle.
 \[r\] is the radius of the circle.
 \[\pi \] or \[pi\] is a mathematical whose value is \[3.14\] .

Note: When we are solve the problems of circumference of circle, at least we have to know the radius of the circle or diameter of the circle, when diameter was given first find the radius of circle by using formula i.e., \[d = \dfrac{r}{2}\] . Don’t forget the \[\pi \] or \[pi\] which is a Greek letter. It is a very important constant in mathematics. Whose value is \[\pi = \dfrac{{22}}{7} = 3.14\] .