Circumference and circular area

This Java code example demonstrates how to calculate the circumference and area of a circle given its radius. The script uses basic mathematical formulas for these calculations and displays the results. This example highlights the use of constants, arithmetic operations, and formatted output in Java.

Code Example

class CircleCalculations {
    public static void main(String[] args) {
        // Declare variables
        double radius = 7.5;
        double circumference, area;
        
        // Calculate circumference
        circumference = 2 * Math.PI * radius;
        
        // Calculate area
        area = Math.PI * radius * radius;
        
        // Print results
        System.out.println("Radius: " + radius);
        System.out.println("Circumference: " + circumference);
        System.out.println("Area: " + area);
    }
}

Code Explanation

public static void main(String[] args)

The main method executes the program and contains the logic for calculating the circumference and area of a circle.

public static void main(String[] args) {
    // Declare variables
    double radius = 7.5;
    double circumference, area;
    
    // Calculate circumference
    circumference = 2 * Math.PI * radius;
    
    // Calculate area
    area = Math.PI * radius * radius;
    
    // Print results
    System.out.println("Radius: " + radius);
    System.out.println("Circumference: " + circumference);
    System.out.println("Area: " + area);
}

Variable Declaration

• double radius = 7.5; declares and initializes the radius of the circle.
• double circumference, area; declares variables to store the circumference and area of the circle.

Calculating Circumference

• circumference = 2 * Math.PI * radius; calculates the circumference using the formula C=2πr, where r is the radius of the circle. Math.PI is a constant provided by the Math class representing the value of π.

Calculating Area

• area = Math.PI * radius * radius; calculates the area using the formula A=πr².

Printing Results

• System.out.println("Radius: " + radius); prints the radius of the circle.
• System.out.println("Circumference: " + circumference); prints the calculated circumference.
• System.out.println("Area: " + area); prints the calculated area.