(1)【抽象类方法】public abstract class Shape {
public abstract double area();
public abstract double perimeter();
}
【圆继承方法】public class Circle extends Shape {//圆面积
private double diameter;
public double getDiameter() {
return diameter;
}
public void setDiameter(double diameter) {
this.diameter = diameter;
}
@Override
public double area() {
return Math.PI * Math.pow(getDiameter() / 2, 2);
}
@Override
public double perimeter() {
return Math.PI * getDiameter();
}
}
【矩形继承】public class Rectangle extends Shape {//矩形周长
private double length;
private double width;
public double getLength() {
return length;
}
public void setLength(double length) {
this.length = length;
}
public double getWidth() {
return width;
}
public void setWidth(double width) {
this.width = w