Question

In a 2 by 3 grid, each lattice point is one unit from it's nearest neighbours. A total of 14 isosceles triangles (but not right triangles), each with an area of 1/2u squared have only two vertices that are one unit appart in the grid. how many such half - unit triangles have at least two vertacies in an x-by-y grid

Answer 1

You can easily sketch the grid, and the triangles, and count.