Question: Pick's theorem says that the area of a simple polygon P in the plane with vertices that are all lattice points (that is, points with integer coordinates) equals I (P ) +B(P )/2 - 1, where I (P ) and B(P ) are the number of lattice points in the interior of P and on the boundary of P, respectively. Use strong induction on the number of vertices of P to prove Pick's theorem.