Radius from Circumference

Introduction to radius from circumference:
In day to day life, we often came across some unique math terms. Radius is one of the special math terms that falls under this category.

Radius of a circle is nothing but the line segment from the center of the circle to its perimeter. In other terms, half the diameter is the radius.

In this article of radius from circumference, we are going to find the radius of the circle from the circumference formula.

Formula for Radius from Circumference:

The Circumference of the circle is given by the following formula:

Circumference =  2`pi`r

If the Circumference C is given, the radius can be calculated by the following formula:

radius  =  `C/(2 pi)`

Example Problems for Finding Radius:
Example 1:

Find the radius, if the circumference of the circle is 100 cm

Solution:

Radius of circle, r  =  `C / ( 2 pi )`

=  `100 / (2 * 3.14)`

=  `100 / 6.28`

=  15.92 cm

Example 2:

Find the radius, if the circumference of the circle is 94 cm

Solution:

Radius of circle, r  =  `C / ( 2 pi )`

=  `94 / (2 * 3.14)`

=  `94 / 6.28`

=  14.97 cm

Example 3:

Find the radius, if the circumference of the circle is 60 mm

Solution:

Radius of circle, r  =  `C / ( 2 pi )`

=  `60 / (2 * 3.14)`

=  `60 / 6.28`

=  9.55 mm

Example 4:

Find the radius, if the circumference of the circle is 35 cm

Solution:

Radius of circle, r  =  `C / ( 2 pi )`

=  `35 / (2 * 3.14)`

=  `35 / 6.28`

=  5.57 cm

Example 5:

Find the radius, if the circumference of the circle is 20 mm

Solution:

Radius of circle, r  =  `C / ( 2 pi )`

=  `20 / (2 * 3.14)`

=  `20 / 6.28`

=  3.18 mm

Example 6:

Find the radius, if the circumference of the circle is 4 m

Solution:

Radius of circle, r  =  `C / ( 2 pi )`

=  `4 / (2 * 3.14)`

=  `4 / 6.28`

=  0.64 m


Practice Problems for Finding Radius:

1) Find the radius, if the circumference of the circle is 50 cm

Answer: 7.96 cm

2) Find the radius, if the circumference of the circle is 20 m

Answer: 3.18 m

3) Find the radius, if the circumference of the circle is 110 mm

Answer: 17.52 mm

4) Find the radius, if the circumference of the circle is 75 cm

Answer: 11.94 cm

5) Find the radius, if the circumference of the circle is 72 mm

Answer: 11.46 mm

Radius of a Circle from Circumference

Radius of a circle from circumference:
The terms radius, diameter and circumference are related to two-dimensional geometric shape named circle. Circle is a two dimensional closed shape with curved edges. The distance between the center of the circle and any point on  the circle  is always same. Circumference of the circle is 2pi r  .where, r is the radius of the circle .

Here radius is the distance between the center of the circle to any point on the circles. Circumference is the total distance around the circle. Let us discuss about the radius from the circumference of the circle,



Example Problem to Find Radius from Circumference:

Example 1:

Find radius of the circle if circumference is 34cm.

Solution:

The classic formula for circumference is `2 pi r`

Therefore,

Circumference =2`pi` r =34cm

Simplify it for radius (r) we get ,

Radius r=`34/2pi`

We know that `pi ` =3.14 or` 22/7`

Therefore, r= `34/(2*3.14)`

=5.41cm

Therefore value of radius from circumference is 5.41cm

Example 2:

Find radius of the circle if circumference is 23cm.

Solution:

The classic formula for circumference is `2 pi r`

Therefore,

Circumference =`2pir` =23cm

Simplify it for radius (r) we get ,

Radius `r=23/2pi`

We know that pi =3.14 or `22/7`

Therefore,` r= 23/(2*3.14)`

=3.66cm

Therefore, value of radius from circumference is 3.66 cm

Example 3:

Find radius of the circle if circumference is 72.4cm.

Solution:

The classic formula for circumference is` 2 pi r`

Therefore,

Circumference =`2pir ` =72.4cm

Simplify it for radius (r) we get ,

Radius r=`72.4/(2pi)`

We know that `pi` =3.14 or `22/7`

Therefore, r=`72.4/(2*3.14)`

=11.52 cm

Therefore, value of radius from circumference is 11.52cm

Example 4:

Find radius of the circle if circumference is 11cm.

Solution:

The classic formula for circumference is `2 pi r`

Therefore,

Circumference =`2pir` =11cm

Simplify it for radius (r) we get ,

Radius r=`11/2pi`

We know that pi =3.14 or `22/7`

Therefore, r= `11/(2*3.14)`

=1.75cm

Therefore, value of radius from circumference is 1.75 cm

Example 5:

Find radius of the circle if circumference is 28inch.

Solution:

The classic formula for circumference is `2 pi r`

Therefore,

Circumference =`2pir ` =28inch

Simplify it for radius (r) we get ,

Radius` r=28/(2pi)`

We know that `pi` =3.14 or `22/7`

Therefore, r= `28/(2*3.14)`

=4.45inch

Therefore, value of radius from circumference is 4.45inch

Is this topic how to measure volume hard for you? Watch out for my coming posts.

Practice Problem to Find Radius from Circumference:

1) Find radius of the circle if circumference is 12cm.

Answer:1.91cm

2)Find radius of the circle if circumference is 44cm.

Answer:7cm