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.

**Formula :**

**Circumference of circle = 2
Π r**

Here the value of Π is either 22/7 or 3.14 and "r" stands for 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 of circle = 2 Πr

= 2 **⋅** (22/7) **⋅** 14

= 2 **⋅** 22 **⋅** 2

= 4 **⋅ **22

= 8 cm

**Example 2:**

Find the diameter of circle whose circumference is 42 cm.

**Solution:**

Circumference of circle = 42 cm

2 Π r = 42

2 **⋅** (22/7) **⋅** r = 42

r = (42 **⋅** 7) / (2 **⋅** 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 **⋅** (22/7) **⋅ **384000 km

= 2413714 km

Hence the distance traveled by the moon = 2413714 km

**Example 4 :**

A copper wire is in the form of a circle with radius 35 cm. It is bent into a square. Determine the side of the square.

**Solution :**

Given: Radius of a circle, r = 35 cm.

Since the same wire is bent into the form of a square,

Perimeter of the circle = Perimeter of the square

Perimeter of the circle = 2Πr units

= 2 **⋅ **(22/7) **⋅ **35

P = 220 cm

Let ‘a’ be the side of a square.

Perimeter of a square = 4a units

4a = 220

a = 55 cm

Side of the square = 55 cm.

After having gone through the stuff above, we hope that the students would have understood circumference of a circle.

Apart from the stuff given on "Circumference of a circle", if you need any other stuff, please use our google custom search here.

HTML Comment Box is loading comments...

You can also visit our following web pages on different stuff in math.

**WORD PROBLEMS**

**Word problems on simple equations **

**Word problems on linear equations **

**Word problems on quadratic equations**

**Area and perimeter word problems**

**Word problems on direct variation and inverse variation **

**Word problems on comparing rates**

**Converting customary units word problems **

**Converting metric units word problems**

**Word problems on simple interest**

**Word problems on compound interest**

**Word problems on types of angles **

**Complementary and supplementary angles word problems**

**Trigonometry word problems**

**Markup and markdown word problems **

**Word problems on mixed fractrions**

**One step equation word problems**

**Linear inequalities word problems**

**Ratio and proportion word problems**

**Word problems on sets and venn diagrams**

**Pythagorean theorem word problems**

**Percent of a number word problems**

**Word problems on constant speed**

**Word problems on average speed **

**Word problems on sum of the angles of a triangle is 180 degree**

**OTHER TOPICS **

**Time, speed and distance shortcuts**

**Ratio and proportion shortcuts**

**Domain and range of rational functions**

**Domain and range of rational functions with holes**

**Graphing rational functions with holes**

**Converting repeating decimals in to fractions**

**Decimal representation of rational numbers**

**Finding square root using long division**

**L.C.M method to solve time and work problems**

**Translating the word problems in to algebraic expressions**

**Remainder when 2 power 256 is divided by 17**

**Remainder when 17 power 23 is divided by 16**

**Sum of all three digit numbers divisible by 6**

**Sum of all three digit numbers divisible by 7**

**Sum of all three digit numbers divisible by 8**

**Sum of all three digit numbers formed using 1, 3, 4**

**Sum of all three four digit numbers formed with non zero digits**