2025 Volume 35 Issue 2 Pages 19-56
Abstract. A lattice point is a point each of whose coordinates is integer. A lattice polygon is a polygon each of whose vertex is a lattice point. Pick’s theorem claims that the area M2(P) of a lattice polygon P equals to I+B/2−1, where I is the number of lattice points contained in the inner region of P, and B is the number of lattice points contained in the boundary of P. In this paper, we give some formulas like Pick’s theorem, one of which calculates volume of a orthogonal polyhedron in R3 using ratio of solid angles.