Polygon2D quad = new Polygon2D(4);
Vektor2D xSub = new Vektor2D(radius * 1.5, 0);
Vektor2D ySub = new Vektor2D(0, radius * 1.5);
Vektor2D zwisch;
zwisch = new Vektor2D(linksOben);
zwisch.sub(xSub);
zwisch.sub(ySub);
quad.add(zwisch);
zwisch = new Vektor2D(linksOben.x, linksOben.y + radius * 4 + radius);
zwisch.sub(xSub);