用java 定义一个抽象类，它包含两个抽象方法面积和周长，从Shape 类派生出三角类，用面积方法来计算面积，用周长来计算周长。然后通过函数设定三角形三边长度为4，5，3，求三角形的面积与周长并输出，且输出三角形的三边长。(输出保留小数点后有效二位)

以下是Java代码实现：

abstract class Shape {
    public abstract double getArea();

    public abstract double getPerimeter();
}

class Triangle extends Shape {
    private double a;
    private double b;
    private double c;

    public Triangle(double a, double b, double c) {
        this.a = a;
        this.b = b;
        this.c = c;
    }

    @Override
    public double getArea() {
        double p = getPerimeter() / 2;
        return Math.sqrt(p * (p - a) * (p - b) * (p - c));
    }

    @Override
    public double getPerimeter() {
        return a + b + c;
    }

    public double getA() {
        return a;
    }

    public double getB() {
        return b;
    }

    public double getC() {
        return c;
    }
}

public class Main {
    public static void main(String[] args) {
        Triangle triangle = new Triangle(4, 5, 3);
        System.out.println("Triangle sides: " + triangle.getA() + " " + triangle.getB() + " " + triangle.getC());
        System.out.printf("Triangle area: %.2f\n", triangle.getArea());
        System.out.printf("Triangle perimeter: %.2f\n", triangle.getPerimeter());
    }
}

运行结果：

Triangle sides: 4.0 5.0 3.0
Triangle area: 6.00
Triangle perimeter: 12.00