package xiti6;
abstract class Shapes{
abstract void area();
abstract void perimeter();
}
class Rectangle extends Shapes{
double a,b;
Rectangle(double a,double b){
this.a=a;
this.b=b;
}
void area(){
System.out.println("矩形的面积是:"+a*b);
}
void perimeter(){
System.out.println("矩形的周长是:"+2*(a+b));
}
}
class Triangle extends Shapes{
double c,d,e,f;
Triangle(double c,double f){
this.c=c;
this.f=f;
}
Triangle(double c,double d,double e){
this.c=c;
this.d=d;
this.e=e;
}
void area(){
System.out.println("三角形的面积是:"+0.5*c*f);
}
void perimeter(){
System.out.println("三角形的周长是:"+(c+d+e));
}
}
class Circles extends Shapes{
double r;
double π=3.1415926;
Circles(double r){
this.r=r;
}
void area(){
System.out.println("圆的面积是:"+π*r*r);
}
void perimeter(){
System.out.println("圆的周长是:"+2*π*r);
}
}
class Oval extends Shapes{
double m,n;
double π=3.1415926;
Oval(double m,double n){
this.m=m;
this.n=n;
}
void area(){
System.out.println("椭圆形的面积是:"+π*m*n);
}
void perimeter(){
System.out.println("椭圆形的周长是:"+(2*π*n+4*(m-n)));
}
}
public class Fifth {
public static void main(String[] args) {
Rectangle rectangle=new Rectangle(2, 4);
rectangle.area();
rectangle.perimeter();
Triangle triangle=new Triangle(2, 1.2);
triangle.area();
Triangle triangles=new Triangle(2,5,3.333);
triangles.perimeter();
Circles circle=new Circles(1.111);
circle.area();
circle.perimeter();
Oval oval=new Oval(3.45189,1.2987345);
oval.area();
oval.perimeter();
}
}