Java Program to Calculate and Display Area of a Circle

Calculating the area of a circle is a basic problem in Java that uses simple mathematical operations. To calculate the area, we need the radius of the circle. The area is calculated using the formula:

Area=π×radius2
Here, we take 𝜋=3.142

Example:

Input: radius = 5
Output: Area of circle is: 78.55
Input: radius = 8
Output: Area of circle is: 201.08

This Java program calculates and displays the area of a circle using a given radius.

public class GFG {
    public static void main(String[] args)
    {
        int radius;
        double pi = 3.142, area;
        radius = 5;
        area = pi * radius * radius;
        System.out.println("Area of circle is: " + area);
    }
}

Area of circle is: 78.55

Explanation:

• The radius is stored in the variable radius.
• The value of π is assigned to pi as 3.142.
• The area is calculated using area = pi * radius * radius.