well you could make 1 triangle that is 6 by 6 by 4
but if you mean as much as possible it would be 4 triangles because you could use 1 cm for each triangle but since there is only 4cm on one of the side which I'm guessing is the bottom part because that is ushally the smallest but you would run out of cm for the 4 bottom part on the 4th triangle so in conclusion 4