Tags: Arithmetic CalculationsFunction //算数计算函数
Given an integer radius R, find the area of a circle.
给定一个整数半径R,求圆的面积
Area of circle = pi * radius * radius.
Where, pi is mathematical constant whose value is 3.14
圆的面积 = pi * 半径 * 半径。
其中,pi 是数学常数,其值为 3.14
Input
4
Output
50.24
Area of circle = 3.14 * 4 * 4 = 50.24
public static void main(String[] args) { DecimalFormat df = new DecimalFormat ("0.00"); Scanner sc = new Scanner(System.in); int r; r = sc.nextInt(); double area=3.14*r*r; System.out.println(df.format(area)); }
输出结果: