java/w4/Triangle.java

// 三角形类，继承抽象类Shape
public class Triangle extends Shape {
    // 底、高
    private double base;
    private double height;

    // 构造方法：初始化底和高
    public Triangle(double base, double height) {
        this.base = base;
        this.height = height;
    }

    // 重写getArea方法：三角形面积 = 底 * 高 / 2
    @Override
    public double getArea() {
        return base * height / 2;
    }

    // 可选：getter/setter方法
    public double getBase() {
        return base;
    }

    public void setBase(double base) {
        this.base = base;
    }

    public double getHeight() {
        return height;
    }

    public void setHeight(double height) {
        this.height = height;
    }
}