The circumference is the distance around a circle. The perimeter of the circle is also called the circumference, which is the total length of the boundary of the circle.

The circumference of circle is the product of the mathematical constant π(Pi) and diameter. It does not matter if the circle is a portion of a sphere or flat. If we know either the diameter or the radius, we can calculate the circumference of a circle.

The circumference is a linear value, and its units are equal to the units of length.

## Parts of a Circle

A circle has many parts:

**Circumference**— The distance around the circle is also called the perimeter of a circle.**Diameter**— The distance from the circle through the circle’s center to the circle on the opposite side, in simple words, diameter, is twice the radius.**Radius**— The distance from the center of a circle to the circle, i.e., half of the diameter. Draw a line component from the center of the circle to any part of the circle to get the radius.

## Circumference Formula

The circumference of the circle is calculated using the formula, then the radius of the circle is taken into account. Hence, we need to know either the value of the radius or the diameter to evaluate the circumference of the circle.

## Diameter to Circumference

If the diameter “d” of the circle is mentioned and the value of the circumference “C” is asked then:

**Circumference (C) = πd**

**Example:** Calculate the circumference of a circle with a diameter of 4 m.

**Solution:**

Given: Diameter = 4 m.

We know that the circumference of a circle using diameter by the formula is πd units.

Further, by, substituting the values in the formula, we get

C = (22/7)(4) m

C = 12.56 m

Therefore, the circumference of the circle is 12.56 m.

## Radius to Circumference

If the radius “r” of the circle is mentioned and the value of the circumference “C” is asked then:

**Circumference (C) = 2πr**

**Example:** Calculate the circumference of a circle with a radius of 3 m.

**Solution:**

Given: Radius = 3 m.

We know that the circumference of a circle using diameter by the formula is 2πr units.

Further, by, substituting the values in the formula, we get

C = (2)(22/7)(3) m

C = 18.857 m

Therefore, the circumference of the circle is 18.857 m.

## Practice Questions

- Calculate the circumference of the circle with the diameter given as 12 cm.
- What will be the diameter of a circle if it’s C = 70 cm?
- If C = 26 cm, what will be its radius?
- Compute the circumference of an 18-inch circle?
- Calculate the circumference of a 6 mm circle?

## Learn Math Online

Online math tutoring is growing in popularity due to the increase in functional technology available. How do you know if learn math online is beneficial or not? There are tons of reasons why online tutoring is useful for your children:

● One-on-one attention – Online math tutoring allows one-on-one math instruction. Math tutoring allows students to receive more individualized lesson plans, as well as to ask questions and bring forward problems they may not have otherwise.

● The comfort of their own home – Asking doubts and participating in math lessons may be rattling in the context of a classroom. Online math tutor allows students to receive math instruction from the comfort of their own home, which increases their ability to ask questions and learn in a way that makes them feel more at ease.

● Different approaches – studying online gives students a wide platform. If a certain approach to a problem is difficult to understand, then one can easily find another approach for the same.

● Less distraction – As Online classes and lectures are set as per students’ schedule, which helps students to decide the time for each activity and set a proper timetable, we eventually help to cut short a lot of distractions.