Construct an equation to calculate the area of a circle
The formula to calculate the area of a circle is given by the equation:

`A = πr²` 

where `A` represents the area of the circle, `r` represents the radius of the circle, and `π` (pi) is a mathematical constant approximately equal to `3.14159`.
Complete the following task based on the instruction and optional input provided.### Instruction:
Construct an equation to calculate the area of a circle

### Output:
The formula to calculate the area of a circle is given by the equation:

`A = πr²` 

where `A` represents the area of the circle, `r` represents the radius of the circle, and `π` (pi) is a mathematical constant approximately equal to `3.14159`.