lader.java

商品交易系统

public class Lader 
{
	double above,bottom,height;
	Lader(double a,double b,double h)
	{
		above=a;
		bottom=b;
		height=h;
	}
	public void setAbove(double a)
	{
		above=a;
	}
	public void setBottom(double b)
	{
		bottom=b;
	}
	public void setHeight(double h)
	{
		height=h;
	}
	double computeArea()
	{
		return(above+bottom)*height/2.0;
	}
	
}