% illusion no 1: le triangle de Kanizsa

% cercle
t=0:pi/200:2*pi;
r=0.3;
x=r*cos(t);
y=r*sin(t);

% centres des cercles
tc=pi/2:2*pi/3:2*pi+pi/2;
xc=cos(tc);
yc=sin(tc);

% représentations
plot(xc,-yc,'k','linewidth',2)
hold on
fill(x+xc(1),y+yc(1),'k',...
     x+xc(2),y+yc(2),'k',...
	 x+xc(3),y+yc(3),'k')
fill(xc,yc,'w','edgecolor','w')

set(gcf,'color','w')
axis off
axis equal
hold off
