设计一个接口Shape,其中声明一个无参方法calcLen())

在该接口基础上实现圆形（Circle）矩形（Rectrangle）三角形（Trianngle）三个类 圆形类属性：半径 矩形类属性：长宽 三角形属性：三条边的长度

public interface  Shape {
    public  double calcLen();
}

public class Circle  implements Shape{
    private double radius;
    public Circle(double radius) {
        this.radius = radius;
    }
    public double getRadius() {
        return radius;
    }
    public void setRadius(double radius) {
        this.radius = radius;
    }

    public double calcLen() {
        return 2 * Math.PI * radius;
    }
}

public class Rectangle implements Shape {
    private double height;
    private double width;
    public Rectangle(double height, double width) {
        this.height = height;
        this.width = width;
    }
    public double getHeight() {
        return height;
    }
    public void setHeight(double height) {
        this.height = height;
    }
    public double getWidth() {
        return width;
    }
    public void setWidth(double width) {
        this.width = width;
    }

    public double calcLen() {
        return 2 * (height + width);
    }
}


public class Triangle implements Shape{
    private double side1;
    private double side2;
    private double side3;
    public Triangle(double side1, double side2, double side3) {
        this.side1 = side1;
        this.side2 = side2;
        this.side3 = side3;
    }
    public double getSide1() {
        return side1;
    }
    public void setSide1(double side1) {
        this.side1 = side1;
    }
    public double getSide2() {
        return side2;
    }
    public void setSide2(double side2) {
        this.side2 = side2;
    }
    public double getSide3() {
        return side3;
    }
    public void setSide3(double side3) {
        this.side3 = side3;
    }


    public double calcLen() {
        return side1 + side2 + side3;
    }
}

如果对你有帮助，记得采纳一下哦~谢谢O(∩_∩)O

可以参考这篇文章，希望对你有帮助：https://blog.csdn.net/w3071206219/article/details/52743727?fps=1&locationNum=1