•
Draw a figure on the retina
•
Choose any two points on the retina
(
p
and
r
)
•
Choose any point q on this line
•
For any one of these triplets, if
p
and
r
are in the figure, but
q
is not, then
the figure is not convex
•
P ___________Q___________ R
•
Defining Convexity