## Circumference of a Circle

Another term of Perimeter of a circle is known as circumference of a circle. This page is going to guide you how to find the perimeter of a circle.  Not only had the procedures we have shown example problems with detailed solution, formulas and practice questions.

Formula

Circumference of circle = 2 Π r

Here the value of Π is either 22/7 or 3.14 and r represents the radius of a circle.

Here the length of the red line is known as circumference of a-circle. Now let us see some example problems to understand this topic better.

Example 1:

Find the circumference of a circle whose radius is 14 cm.

Solution:

To find the circumference of circle we need to use the formula to find the circumference of circle.

Circumference = 2 Πr

= 2 x (22/7) x 14

= 2 x 22 x 2

= 4 x 22

= 8 cm

Example 2:

Find the diameter of circle whose circumference is 42 cm.

Solution:

Before finding diameter of-a circle first we have to find the radius of a circle. Then we have to multiply the radius by 2 to get the diameter.

Circumference of circle = 42 cm

2 Π r = 42

2 x (22/7) x r = 42

r = (42 x 7) / (2 x 22)

r = 294/44

r = 6.68 cm

Now we have to find the diameter for that we have to multiply the radius by 2.

Diameter = 2 r

= 2(6.68)

= 13.36 cm

Example 3:

A moon is about 384000 km away from the earth and its path around the earth is nearly circular. Find the distance traveled by moon every month.

Solution:

In one month, the moon describes a full circle about the earth.

Now the circumference = 2 Π r

=  2 x (22/7) x 384000 km

=  2413714 km

Hence the distance traveled by moon every month = 2413714 km