java之2.封装一类梯形对象Ladder，该类对象具有上底、下底和高的属性，具有初始化梯形的功能、修改上底、下底和高的功能、求周长的功能、求面积的功能。

package hu;

public class Ladder {
private double a,b,h,c;
public Ladder(double a,double b,double h,double c){
this.a=a;
this.b=b;
this.h=h;
this.c=c;
}
public void set_a(double a){
this.a=a;
}
public void set_b(double b){
this.b=b;
}
public void set_h(double h){
this.h=h;
}
public void set_c(double c){
this.c=c;
}
public double get_a(){
return a;
}
public double get_b(){
return b;
}
public double get_h(){
return h;
}
public double get_c(){
return c;
}
//求周长不会
public void circum(){
double c1=0;
c1=a+b+2*c;
System.out.println("梯形上底，下底，高,腰为："+a+" "+b+" "+" "+h+" "+c);
System.out.println("梯形周长为："+c1);

}
public void area(){
double s=0;
s=(a+b)*h/2;
System.out.println("梯形上底，下底，高,腰为："+a+" "+b+" "+" "+h+" "+c);
System.out.println("梯形面积为："+s);
}
public static void main(String[] args) {
// TODO Auto-generated method stub
Ladder la=new Ladder(2,10,3,5);
la.area();
la.circum();
}

}