java代码终于过百行了
/* 求三角形,圆。梯形周长及面积的代码 */ class Trangle { double sideA,sideB,sideC,area,length; boolean boo; public Trangle(double a,double b,double c) { sideA=a; sideB=b; sideC=c; if(a+b>c&&a+c>b&&b+c>a) { boo=true; } else { boo=false; } } double getLength() { if(boo) { length=sideA+sideB+sideC; return length; } else { System.out.println("not a trangle"); return 0; } } 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("not a trangle"); return 0; } } public void setABC(double a,double b,double c) { sideA=a;sideB=b;sideC=c; if(a+b>c&&a+c>b&&b+c>a) { boo=true; } else { boo=false; } } } class Lader { double above,bottom,height,area; Lader(double a,double b,double h) { above=a; bottom=b; height=h; } double getArea() { area=(above+bottom)/2*height; return area; } } class Circle { double radius,area; Circle(double r) { radius=r; } double getArea() { return(3.14*radius*radius); } double getLength() { return(3.14*2*radius); } void setRadius(double newRadius) { radius=newRadius; } double getRadius() { return radius; } } public class AreaAndLength { public static void main(String args[]) { double length,area; Circle circle=null; Trangle trangle; Lader lader; circle=new Circle(10); trangle=new Trangle(3,4,5); lader=new Lader(3,4,10); length=trangle.getLength(); System.out.println("圆的周长:"+length); area=trangle.getArea(); System.out.println("圆的面积"+area); length=trangle.getLength(); System.out.println("三角形的周长:"+length); area=trangle.getArea(); System.out.println("三角形的面积:"+area); area=lader.getArea(); System.out.println("梯形的面积:"+area); trangle.setABC(12,34,1); area=trangle.getArea(); System.out.println("三角形的面积:"+area); length=trangle.getLength(); System.out.println("三角形的周长:"+length); } }