Negative Space ExperienceI REALLY simplify this concept to my high school students. I put my hand on my head, forming a "V" with my arm. I discuss how if they just try to draw the arm itself that chances are part of the arm will be too long, angles will be wrong, and they may struggle getting it right. BUT, if they try drawing that triangle in the center then that will fix the problem. Simple, but they understand. :-)
~Michal