Kendra has an unlimited supply of unbreakable sticks of length 2, 4 and 6 inches. Using these sticks, how many non-congruent triangles can she make if each side is made with a whole stick? two sticks can be joined only at a vertex of the triangle. (a triangle with sides of lengths 4, 6, 6 is an example of one such triangle to be included, whereas a triangle with sides of lengths 2, 2, 4 should not be included. ).