**We can use the following formula for finding the circumference (****perimeter**) of a circle:

**We can use the code:**

using System;
class CirclePerimeter
{
static void Main()
// Perimeter (Circumference) of a circle: C=2πr
{
Console.WriteLine("Please write the radius of your circle and hit Enter afterwards: ");
double radius = double.Parse(Console.ReadLine());
double pi = Math.PI;
double area = 2 * pi * radius;
Console.WriteLine("The Perimeter or Circumference (C=2πr) of your circle is: {0:F2}", area);
}
}