Write a program

Question

to calculate area of circle using functions

Answer 1

Is it a challenge ?
If yes, then just ignore my answer ^^
If no (if it is a request), here is the formula of the area of a circle, it is quite easy to apply it in a program. If you still have troubles with it, just tell us where your trouble is and we will help :)

Area of a circle of rayon r :
PI * r * r

Answer 2

Writen in C#:

double radius = 0;
double area = 0;

Console.Write("Input the radius: ");
radius = Convert.ToDouble(Console.ReadLine());
area = Math.PI * radius * radius;

Console.WriteLine(quot;Area = {area}");