面积

[java]代码库

package chapter2;
import java.util.Scanner;
class Zyy {
	double a;
	double b;
	double c;
	double s,area;
	double radius;
	double Triangle(){
	if ((a+b)<=c||(b+c)<=a||(c+a)<=b)
			System.out.println("ERROR!");
		else{
			s=(a+b+c)/2;
			area=Math.sqrt(s*(s-a)*(s-b)*(s-c));
			}
	return area;
	}
	double Circle() {
		area=3.14*radius*radius;
		return area;
	}	
	}
public class Shape
{
	public static void main (String[] args)
   {
	  double A,B,C,r,area1,area2;
	   System.out.print("三角形的边长：\n");
      Scanner cin = new Scanner(System.in);
      Zyy s=new Zyy();
      A=cin.nextInt();
      B=cin.nextInt();
      C=cin.nextInt();
      s.a=A;
      s.b=B;
      s.c=C;
      area2=s.Triangle();
      System.out.print("三角形的面积为："+area2);
      System.out.printf("圆的半径：");
      r=cin.nextInt();
          s.radius=r;
          area1=s.Circle();
          System.out.printf("圆的面积为："+area1);
	}
}