Prove that S(ABC) is no larger than 9/2
Source:
September 19, 2010
analytic geometrygeometry
Problem Statement
In coordinate plane, we call a point "lattice point" if both and are integers. Knowing that the vertices of triangle are all lattice points, and there exists exactly one lattice point interior to triangle (there might exist lattice points on the sides of ). Prove that the area of triangle is no larger than