定义Triangle类，要求实现IShape接口，定义三个顶点；定义无参和带参构造方法；定义set和get方法；moveTo方法实现将三角形的中心点位置移动到指定的位置（假设中心点位置的x、y分别为三个顶点坐标的均值）；实现zoom方法，主要是对任意两个顶点的坐标值进行缩放；

public class Triangle implements IShape {
    private Point vertex1;
    private Point vertex2;
    private Point vertex3;

    public Triangle() {
        this.vertex1 = new Point();
        this.vertex2 = new Point();
        this.vertex3 = new Point();
    }

    public Triangle(Point vertex1, Point vertex2, Point vertex3) {
        this.vertex1 = vertex1;
        this.vertex2 = vertex2;
        this.vertex3 = vertex3;
    }

    public void setVertex1(Point vertex1) {
        this.vertex1 = vertex1;
    }

    public void setVertex2(Point vertex2) {
        this.vertex2 = vertex2;
    }

    public void setVertex3(Point vertex3) {
        this.vertex3 = vertex3;
    }

    public Point getVertex1() {
        return vertex1;
    }

    public Point getVertex2() {
        return vertex2;
    }

    public Point getVertex3() {
        return vertex3;
    }

    @Override
    public void moveTo(int x, int y) {
        int centerX = (vertex1.getX() + vertex2.getX() + vertex3.getX()) / 3;
        int centerY = (vertex1.getY() + vertex2.getY() + vertex3.getY()) / 3;
        int deltaX = x - centerX;
        int deltaY = y - centerY;
        vertex1.moveTo(vertex1.getX() + deltaX, vertex1.getY() + deltaY);
        vertex2.moveTo(vertex2.getX() + deltaX, vertex2.getY() + deltaY);
        vertex3.moveTo(vertex3.getX() + deltaX, vertex3.getY() + deltaY);
    }

    @Override
    public void zoom(double ratio) {
        vertex1.setX((int) (vertex1.getX() * ratio));
        vertex1.setY((int) (vertex1.getY() * ratio));
        vertex2.setX((int) (vertex2.getX() * ratio));
        vertex2.setY((int) (vertex2.getY() * ratio));
        vertex3.setX((int) (vertex3.getX() * ratio));
        vertex3.setY((int) (vertex3.getY() * ratio));
    }
}