# 10 Digits Of pi

pi or `pi` is a mathematical constant whose value is the ratio of any circle's circumference to its diameter in Euclidean space; this is the same value as the ratio of a circle's area to the square of its radius. It is approximately equal to 3.141593 in the usual decimal notation. 3.1428571428 is approximate value for pi in 10 digits. Here we are going to solve some problems using the value of 10 digits of pi.(Source: From Wikipedia).

## Problems using the value of 10 digits of pi

Example 1

Find the area and circumference of a circle whose radius is 3 m, use pi = 10 digits of pi.

Solution

The area of a circle is given by the formula, A = pi `r^2` square units

Here, r = 3m

10 digits of pi = 3.1428571428

Area of the circle = 3.1428571428 * `3^2`

= 3.1428571428 * 3 * 3

= 28.2857143 m2

So the area of the circle using 10 digits of pi is 28.2857143 m2.

Circumference of the circle = 2 pi r

pi = 3.1428571428

r = 3

Circumference = 2 * 3.1428571428 * 3

= 18.8571429 m

The circumference of the circle is 18.8571429 m

## Example 2

Example 2

What is the area of a circle with radius 6 cm, use pi = 10 digits of pi.

Solution

The area of a circle is given by the formula, A = pi r2 square units

Here, r = 6 cm

10 digits of pi = 3.1428571428

Area of the circle = 3.1428571428 * 62

= 3.1428571428 * 6 * 6

=113.142857  cm2

So the area of the circle using 10 digits of pi is 113.142857 cm2.

Example 3

The circumference of a circle is 23.25421512 cm. What is the area of the circle. Use 10 digits of pi.

Solution

Circumference of circle = 2 pi r

pi = 3.1428571428

2 * 3.1428571428 * r = 23.25421512

6.28571429 r = 23.25421512

r = 23.25421512/6.28571429

r = 3.69953422 m

Area of the circle = pi `r^2`

pi  = 3.1428571428

r = 3.69953422 m

area of the circle = 3.1428571428 * 3.69953422 * 3.69953422

=  43.0148823 m2