利用Java计算圆的面积

计算圆的面积

import java.util.Scanner;

public class yuan {
public static void main(String[] args) {
double radius;
double area;
Scanner input = new Scanner(System.in);
System.out.println(“请输入半径值：”);
radius = input.nextDouble();
area = Math.PI * radius *radius;
System.out.println(“圆的面积为：” + area);
}
}