One of the most famous proposed solutions is that da Vinci embedded the Golden ratio in this work. “The question that’s being asked is about the ratio that Da Vinci uses,” says Mac Sweeney. So what’s going wrong with the modern human jaw, Mac Sweeney thought. “Why is there a disproportion between the human jaw and the human dentition?” Mac Sweeney says. Because da Vinci’s and Bonwill’s triangles correspond, Mac Sweeney says, this shows that tetrahedron geometry can also be used to understand da Vinci’s drawing.