1.单击
2.单击
3.在代码编辑器中输入以下代码
public class AreaAndLength {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubdouble length,area;Circle circle=null;Triangle triangle;Ladder ladder;circle=new Circle(6);triangle=new Triangle(3,4,5);ladder=new Ladder(3,4,5);length=circle.getLength();System.out.println(“圆的周长：”+length);area=circle.getArea();System.out.println(“圆的面积：”+area);length=triangle.getLength();System.out.println(“三角形的周长：”+length);area=triangle.getArea();System.out.println(“三角形的面积：”+area);area=ladder.getArea();System.out.println(“梯形的面积：”+area);triangle.setABC(12.0,34.0,1.0);area=triangle.getArea();System.out.println(“三角形的面积：”+area);length=triangle.getLength();System.out.println(“三角形的周长：”+length);}}class Triangle{double sideA,sideB,sideC,area,length;boolean boo;public Triangle(double a,double b,double c){sideA=a;sideB=b;sideC=c;if(a+b>c&&a+c>b&&b+c>a&&a-b<c&&a-c<b&&b-a<c&&b-c<a&&c-a<b&&c-b<a){boo=true;}else{boo=false;}}double getLength(){length=sideA+sideB+sideC;return length;}public double getArea(){if(boo){double p=(sideA+sideB+sideC)/2.0;area=Math.sqrt(p*(p-sideA)*(p-sideB)*(p-sideC));return area;}else{System.out.println(“不是一个三角形，服务器空间，美国空间，香港空间，不能计算面积”);return 0;}}public void setABC(double a,double b,double c){sideA=a;sideB=b;sideC=c;}}class Ladder{double above,bottom,height,area;Ladder(double a,double b,double h){above=a;bottom=b;height=h;}double getArea(){area=(above+bottom)*height/2;return area;}}class Circle{double radius,area,length;Circle(double r){radius=r;}double getArea(){area=3.14159265*radius*radius;return area;}double getLength(){length=2*3.14159265*radius;return length;}void setRadius(double newRadius){radius=newRadius;}double getRadius(){return radius;}}我就想是一只草原中被牧童遗忘的羊，
