Question

What is $\pi$ ?

Answer 1

Hint: The symbol $\pi$ is widely used in the formulae of mathematics and physics. It is a mathematical constant and has various equivalent definitions. It is usually defined as the ratio of the circumference of a circle to its diameter.

Complete step by step solution:
The number $\pi$ is a mathematical constant is a key number that assumes the same value irrespective of the change in other parameters. The symbol $\pi$ is a mathematical constant.
The symbol $\pi$ is used in many formulae in mathematics.
A circle is a two-dimensional figure in which a set of points are at a fixed distance from a center. The diameter is a line that divides a circle into two halves and is twice the radius of the circle.
The circumference of a circle is the perimeter of a circle. It is usually the linear distance around the circle.
It is usually denoted by the variable C.
The circumference of the circle is given as follows,
$\Rightarrow C=2\pi r$
Here,
C is the circumference of the circle
$\pi$ is the mathematical constant
$r$ is the radius of the circle
The diameter of the circle is the straight line passing from the center of the circle.
The diameter can be diagrammatically represented as follows,

From the figure,
d is the diameter of the circle
O is the center of the circle
The symbol $\pi$ is usually defined as the ratio of the circle's circumference to its diameter.
It is mathematically given as follows,
$\Rightarrow \pi =\dfrac{C}{d}$
Here,
C is the circumference of the circle
d is the diameter of the circle

Note: A symbol $\pi$ is an irrational number whose value is equal to $3.14\;$ and so it can not be represented in the form of a fraction. The fraction $\dfrac{22}{7}$ is used to approximately represent $\pi$ but no fraction can express its exact value.