How to Calculate Area of Circle in C#?

C# is a general-purpose, modern and object-oriented programming language pronounced as “C Sharp”. In this article, we will see how to calculate the area of a circle in C#. 

The area of a circle can be evaluated using the formula:

Area of circle  = pi * r * r   //where r is the radius of circle

Example 1:

C#

// Program to implement area of circle in C#
using System;
class Circle
{
    static void Main(string[] args)
    {
        Console.Write("Enter Radius: ");
        double rad = Convert.ToDouble(Console.ReadLine());
        double area = Math.PI * rad * rad;
        Console.WriteLine("Area of circle is: " + area);
    }
}

Output:

Code Explanation:

The formula used to calculate the circle area: π * r * r. Where, r is the radius and π is the mathematical constant Pi. We will take the value of radius from the user as input. For π, we can either define a variable and assign it up to a specific decimal place or we can use Math.PI constant that is available in C#.

• The Radius is a double value to keep the radius of the circle.
• The area is double to save the area of the circle.
• The final area is stored in the double area.
• Finally, we are writing down the area of a circle.