摘要： class Lader{double above,bottom,height;Lader(){}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;}}public cla 阅读全文