What is Circle?
A circle is a round shaped figure that has no corners or edges. If you have a radius for a circle, you could easily find out Area, Diameter and Circumference for a Circle.
Here are the formulas for the Circle.
- Area: A=πr2 (π = 3.14)
- Perimeter (Circumference): C=2πr (π = 3.14)
- Diameter: d=2r
Here is a simple Java program to find out Diameter, Area and Circumference of any given circle provided you have radius.
Create class CrunchifyCircleDiameterAreaCircumference.java
package crunchify.com.java.tutorials;
import java.text.DecimalFormat;
import java.util.Scanner;
/**
* @author Crunchify.com
* In Java How to find Diameter, Area and Circumference for a Circle?
*/
public class CrunchifyCircleDiameterAreaCircumference {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
crunchifyPrint("Enter a Circle Radius: ");
double crunchifyRadius = sc.nextDouble();
// Diameter = d=2r
// Area = 2 x crunchifyRadius
double crunchifyDiameter = 2 * crunchifyRadius;
crunchifyPrint("===> Diameter: " + crunchifyDiameter);
DecimalFormat df = new DecimalFormat("0.000000");
// Area = A=πr2 (π = 3.14)
// Area = PI * crunchifyRadius * crunchifyRadius
double crunchifyArea = Math.PI * (crunchifyRadius * crunchifyRadius);
crunchifyPrint("===> Area: " + df.format(crunchifyArea));
// Circumference = C=2πr (π = 3.14)
// Circumference = 2 * PI * crunchifyRadius
double crunchifyCircumference = Math.PI * 2 * crunchifyRadius;
crunchifyPrint("===> Circumference: " + df.format(crunchifyCircumference));
}
private static void crunchifyPrint(String s) {
System.out.println(s);
}
}
Result:
Just run above program as a Java Program in Eclipse or IntelliJ IDEA.
Enter a Circle Radius: 5 ===> Diameter: 10.0 ===> Area: 78.539816 ===> Circumference: 31.415927 Process finished with exit code 0
Enter a Circle Radius: 10 ===> Diameter: 20.0 ===> Area: 314.159265 ===> Circumference: 62.831853 Process finished with exit code 0