package lei;
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(){
return length=sideA+sideB+sideC;
}
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("不是三角形，不能计算面积");
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(){
return area=((above+bottom)*height)/2.0;
}
}
class Circle{
double radius,length,area;
Circle(double r){
radius=r;
}
double getArea(){
return area=3.14*radius*radius;
}
double getLength(){
return length=3.14*2*radius;
}
void setRadius(double newRadius){
radius=newRadius;
}
double getRadius(){
return radius;
}
}
2./**
* @author pc
* @Time 2018年4月20日 下午5:59:48
* @Version 1.0
*
*/
package lei;
public class AreaAndLength {
public static void main (String[] args){
double length,area;
Circle circle=null;
Trangle trangle;
Lader lader;
circle=new Circle(2);
trangle=new Trangle(3,4,5);
lader=new Lader(2,6,6);
length=circle.getLength();
System.out.println("圆的周长"+length);
area=circle.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);
}
}